SemaStmt.cpp source code [clang_source_code/lib/Sema/SemaStmt.cpp]

1	//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This file implements semantic analysis for statements.
10	//
11	//===----------------------------------------------------------------------===//
12
13	#include "clang/Sema/SemaInternal.h"
14	#include "clang/AST/ASTContext.h"
15	#include "clang/AST/ASTDiagnostic.h"
16	#include "clang/AST/ASTLambda.h"
17	#include "clang/AST/CharUnits.h"
18	#include "clang/AST/CXXInheritance.h"
19	#include "clang/AST/DeclObjC.h"
20	#include "clang/AST/EvaluatedExprVisitor.h"
21	#include "clang/AST/ExprCXX.h"
22	#include "clang/AST/ExprObjC.h"
23	#include "clang/AST/RecursiveASTVisitor.h"
24	#include "clang/AST/StmtCXX.h"
25	#include "clang/AST/StmtObjC.h"
26	#include "clang/AST/TypeLoc.h"
27	#include "clang/AST/TypeOrdering.h"
28	#include "clang/Basic/TargetInfo.h"
29	#include "clang/Lex/Preprocessor.h"
30	#include "clang/Sema/Initialization.h"
31	#include "clang/Sema/Lookup.h"
32	#include "clang/Sema/Scope.h"
33	#include "clang/Sema/ScopeInfo.h"
34	#include "llvm/ADT/ArrayRef.h"
35	#include "llvm/ADT/DenseMap.h"
36	#include "llvm/ADT/STLExtras.h"
37	#include "llvm/ADT/SmallPtrSet.h"
38	#include "llvm/ADT/SmallString.h"
39	#include "llvm/ADT/SmallVector.h"
40
41	using namespace clang;
42	using namespace sema;
43
44	StmtResult Sema::ActOnExprStmt(ExprResult FE, bool DiscardedValue) {
45	if (FE.isInvalid())
46	return StmtError();
47
48	FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(), DiscardedValue);
49	if (FE.isInvalid())
50	return StmtError();
51
52	// C99 6.8.3p2: The expression in an expression statement is evaluated as a
53	// void expression for its side effects. Conversion to void allows any
54	// operand, even incomplete types.
55
56	// Same thing in for stmt first clause (when expr) and third clause.
57	return StmtResult(FE.getAs<Stmt>());
58	}
59
60
61	StmtResult Sema::ActOnExprStmtError() {
62	DiscardCleanupsInEvaluationContext();
63	return StmtError();
64	}
65
66	StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc,
67	bool HasLeadingEmptyMacro) {
68	return new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro);
69	}
70
71	StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc,
72	SourceLocation EndLoc) {
73	DeclGroupRef DG = dg.get();
74
75	// If we have an invalid decl, just return an error.
76	if (DG.isNull()) return StmtError();
77
78	return new (Context) DeclStmt(DG, StartLoc, EndLoc);
79	}
80
81	void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) {
82	DeclGroupRef DG = dg.get();
83
84	// If we don't have a declaration, or we have an invalid declaration,
85	// just return.
86	if (DG.isNull() \|\| !DG.isSingleDecl())
87	return;
88
89	Decl *decl = DG.getSingleDecl();
90	if (!decl \|\| decl->isInvalidDecl())
91	return;
92
93	// Only variable declarations are permitted.
94	VarDecl *var = dyn_cast<VarDecl>(decl);
95	if (!var) {
96	Diag(decl->getLocation(), diag::err_non_variable_decl_in_for);
97	decl->setInvalidDecl();
98	return;
99	}
100
101	// foreach variables are never actually initialized in the way that
102	// the parser came up with.
103	var->setInit(nullptr);
104
105	// In ARC, we don't need to retain the iteration variable of a fast
106	// enumeration loop. Rather than actually trying to catch that
107	// during declaration processing, we remove the consequences here.
108	if (getLangOpts().ObjCAutoRefCount) {
109	QualType type = var->getType();
110
111	// Only do this if we inferred the lifetime. Inferred lifetime
112	// will show up as a local qualifier because explicit lifetime
113	// should have shown up as an AttributedType instead.
114	if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) {
115	// Add 'const' and mark the variable as pseudo-strong.
116	var->setType(type.withConst());
117	var->setARCPseudoStrong(true);
118	}
119	}
120	}
121
122	/// Diagnose unused comparisons, both builtin and overloaded operators.
123	/// For '==' and '!=', suggest fixits for '=' or '\|='.
124	///
125	/// Adding a cast to void (or other expression wrappers) will prevent the
126	/// warning from firing.
127	static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) {
128	SourceLocation Loc;
129	bool CanAssign;
130	enum { Equality, Inequality, Relational, ThreeWay } Kind;
131
132	if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) {
133	if (!Op->isComparisonOp())
134	return false;
135
136	if (Op->getOpcode() == BO_EQ)
137	Kind = Equality;
138	else if (Op->getOpcode() == BO_NE)
139	Kind = Inequality;
140	else if (Op->getOpcode() == BO_Cmp)
141	Kind = ThreeWay;
142	else {
143	isRelationalOp()", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 143, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Op->isRelationalOp());
144	Kind = Relational;
145	}
146	Loc = Op->getOperatorLoc();
147	CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue();
148	} else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) {
149	switch (Op->getOperator()) {
150	case OO_EqualEqual:
151	Kind = Equality;
152	break;
153	case OO_ExclaimEqual:
154	Kind = Inequality;
155	break;
156	case OO_Less:
157	case OO_Greater:
158	case OO_GreaterEqual:
159	case OO_LessEqual:
160	Kind = Relational;
161	break;
162	case OO_Spaceship:
163	Kind = ThreeWay;
164	break;
165	default:
166	return false;
167	}
168
169	Loc = Op->getOperatorLoc();
170	CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue();
171	} else {
172	// Not a typo-prone comparison.
173	return false;
174	}
175
176	// Suppress warnings when the operator, suspicious as it may be, comes from
177	// a macro expansion.
178	if (S.SourceMgr.isMacroBodyExpansion(Loc))
179	return false;
180
181	S.Diag(Loc, diag::warn_unused_comparison)
182	<< (unsigned)Kind << E->getSourceRange();
183
184	// If the LHS is a plausible entity to assign to, provide a fixit hint to
185	// correct common typos.
186	if (CanAssign) {
187	if (Kind == Inequality)
188	S.Diag(Loc, diag::note_inequality_comparison_to_or_assign)
189	<< FixItHint::CreateReplacement(Loc, "\|=");
190	else if (Kind == Equality)
191	S.Diag(Loc, diag::note_equality_comparison_to_assign)
192	<< FixItHint::CreateReplacement(Loc, "=");
193	}
194
195	return true;
196	}
197
198	void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
199	if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S))
200	return DiagnoseUnusedExprResult(Label->getSubStmt());
201
202	const Expr *E = dyn_cast_or_null<Expr>(S);
203	if (!E)
204	return;
205
206	// If we are in an unevaluated expression context, then there can be no unused
207	// results because the results aren't expected to be used in the first place.
208	if (isUnevaluatedContext())
209	return;
210
211	SourceLocation ExprLoc = E->IgnoreParenImpCasts()->getExprLoc();
212	// In most cases, we don't want to warn if the expression is written in a
213	// macro body, or if the macro comes from a system header. If the offending
214	// expression is a call to a function with the warn_unused_result attribute,
215	// we warn no matter the location. Because of the order in which the various
216	// checks need to happen, we factor out the macro-related test here.
217	bool ShouldSuppress =
218	SourceMgr.isMacroBodyExpansion(ExprLoc) \|\|
219	SourceMgr.isInSystemMacro(ExprLoc);
220
221	const Expr *WarnExpr;
222	SourceLocation Loc;
223	SourceRange R1, R2;
224	if (!E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context))
225	return;
226
227	// If this is a GNU statement expression expanded from a macro, it is probably
228	// unused because it is a function-like macro that can be used as either an
229	// expression or statement. Don't warn, because it is almost certainly a
230	// false positive.
231	if (isa<StmtExpr>(E) && Loc.isMacroID())
232	return;
233
234	// Check if this is the UNREFERENCED_PARAMETER from the Microsoft headers.
235	// That macro is frequently used to suppress "unused parameter" warnings,
236	// but its implementation makes clang's -Wunused-value fire. Prevent this.
237	if (isa<ParenExpr>(E->IgnoreImpCasts()) && Loc.isMacroID()) {
238	SourceLocation SpellLoc = Loc;
239	if (findMacroSpelling(SpellLoc, "UNREFERENCED_PARAMETER"))
240	return;
241	}
242
243	// Okay, we have an unused result. Depending on what the base expression is,
244	// we might want to make a more specific diagnostic. Check for one of these
245	// cases now.
246	unsigned DiagID = diag::warn_unused_expr;
247	if (const FullExpr *Temps = dyn_cast<FullExpr>(E))
248	E = Temps->getSubExpr();
249	if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E))
250	E = TempExpr->getSubExpr();
251
252	if (DiagnoseUnusedComparison(*this, E))
253	return;
254
255	E = WarnExpr;
256	if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
257	if (E->getType()->isVoidType())
258	return;
259
260	if (const Attr *A = CE->getUnusedResultAttr(Context)) {
261	Diag(Loc, diag::warn_unused_result) << A << R1 << R2;
262	return;
263	}
264
265	// If the callee has attribute pure, const, or warn_unused_result, warn with
266	// a more specific message to make it clear what is happening. If the call
267	// is written in a macro body, only warn if it has the warn_unused_result
268	// attribute.
269	if (const Decl *FD = CE->getCalleeDecl()) {
270	if (ShouldSuppress)
271	return;
272	if (FD->hasAttr<PureAttr>()) {
273	Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
274	return;
275	}
276	if (FD->hasAttr<ConstAttr>()) {
277	Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const";
278	return;
279	}
280	}
281	} else if (ShouldSuppress)
282	return;
283
284	if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
285	if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) {
286	Diag(Loc, diag::err_arc_unused_init_message) << R1;
287	return;
288	}
289	const ObjCMethodDecl *MD = ME->getMethodDecl();
290	if (MD) {
291	if (const auto *A = MD->getAttr<WarnUnusedResultAttr>()) {
292	Diag(Loc, diag::warn_unused_result) << A << R1 << R2;
293	return;
294	}
295	}
296	} else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
297	const Expr *Source = POE->getSyntacticForm();
298	if (isa<ObjCSubscriptRefExpr>(Source))
299	DiagID = diag::warn_unused_container_subscript_expr;
300	else
301	DiagID = diag::warn_unused_property_expr;
302	} else if (const CXXFunctionalCastExpr *FC
303	= dyn_cast<CXXFunctionalCastExpr>(E)) {
304	const Expr *E = FC->getSubExpr();
305	if (const CXXBindTemporaryExpr *TE = dyn_cast<CXXBindTemporaryExpr>(E))
306	E = TE->getSubExpr();
307	if (isa<CXXTemporaryObjectExpr>(E))
308	return;
309	if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(E))
310	if (const CXXRecordDecl *RD = CE->getType()->getAsCXXRecordDecl())
311	if (!RD->getAttr<WarnUnusedAttr>())
312	return;
313	}
314	// Diagnose "(void*) blah" as a typo for "(void) blah".
315	else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) {
316	TypeSourceInfo *TI = CE->getTypeInfoAsWritten();
317	QualType T = TI->getType();
318
319	// We really do want to use the non-canonical type here.
320	if (T == Context.VoidPtrTy) {
321	PointerTypeLoc TL = TI->getTypeLoc().castAs<PointerTypeLoc>();
322
323	Diag(Loc, diag::warn_unused_voidptr)
324	<< FixItHint::CreateRemoval(TL.getStarLoc());
325	return;
326	}
327	}
328
329	if (E->isGLValue() && E->getType().isVolatileQualified()) {
330	Diag(Loc, diag::warn_unused_volatile) << R1 << R2;
331	return;
332	}
333
334	DiagRuntimeBehavior(Loc, nullptr, PDiag(DiagID) << R1 << R2);
335	}
336
337	void Sema::ActOnStartOfCompoundStmt(bool IsStmtExpr) {
338	PushCompoundScope(IsStmtExpr);
339	}
340
341	void Sema::ActOnFinishOfCompoundStmt() {
342	PopCompoundScope();
343	}
344
345	sema::CompoundScopeInfo &Sema::getCurCompoundScope() const {
346	return getCurFunction()->CompoundScopes.back();
347	}
348
349	StmtResult Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
350	ArrayRef<Stmt *> Elts, bool isStmtExpr) {
351	const unsigned NumElts = Elts.size();
352
353	// If we're in C89 mode, check that we don't have any decls after stmts. If
354	// so, emit an extension diagnostic.
355	if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) {
356	// Note that __extension__ can be around a decl.
357	unsigned i = 0;
358	// Skip over all declarations.
359	for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
360	/empty/;
361
362	// We found the end of the list or a statement. Scan for another declstmt.
363	for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
364	/empty/;
365
366	if (i != NumElts) {
367	Decl D = cast<DeclStmt>(Elts[i])->decl_begin();
368	Diag(D->getLocation(), diag::ext_mixed_decls_code);
369	}
370	}
371
372	// Check for suspicious empty body (null statement) in `for' and `while'
373	// statements. Don't do anything for template instantiations, this just adds
374	// noise.
375	if (NumElts != 0 && !CurrentInstantiationScope &&
376	getCurCompoundScope().HasEmptyLoopBodies) {
377	for (unsigned i = 0; i != NumElts - 1; ++i)
378	DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]);
379	}
380
381	return CompoundStmt::Create(Context, Elts, L, R);
382	}
383
384	ExprResult
385	Sema::ActOnCaseExpr(SourceLocation CaseLoc, ExprResult Val) {
386	if (!Val.get())
387	return Val;
388
389	if (DiagnoseUnexpandedParameterPack(Val.get()))
390	return ExprError();
391
392	// If we're not inside a switch, let the 'case' statement handling diagnose
393	// this. Just clean up after the expression as best we can.
394	if (!getCurFunction()->SwitchStack.empty()) {
395	Expr *CondExpr =
396	getCurFunction()->SwitchStack.back().getPointer()->getCond();
397	if (!CondExpr)
398	return ExprError();
399	QualType CondType = CondExpr->getType();
400
401	auto CheckAndFinish = [&](Expr *E) {
402	if (CondType->isDependentType() \|\| E->isTypeDependent())
403	return ExprResult(E);
404
405	if (getLangOpts().CPlusPlus11) {
406	// C++11 [stmt.switch]p2: the constant-expression shall be a converted
407	// constant expression of the promoted type of the switch condition.
408	llvm::APSInt TempVal;
409	return CheckConvertedConstantExpression(E, CondType, TempVal,
410	CCEK_CaseValue);
411	}
412
413	ExprResult ER = E;
414	if (!E->isValueDependent())
415	ER = VerifyIntegerConstantExpression(E);
416	if (!ER.isInvalid())
417	ER = DefaultLvalueConversion(ER.get());
418	if (!ER.isInvalid())
419	ER = ImpCastExprToType(ER.get(), CondType, CK_IntegralCast);
420	return ER;
421	};
422
423	ExprResult Converted = CorrectDelayedTyposInExpr(Val, CheckAndFinish);
424	if (Converted.get() == Val.get())
425	Converted = CheckAndFinish(Val.get());
426	if (Converted.isInvalid())
427	return ExprError();
428	Val = Converted;
429	}
430
431	return ActOnFinishFullExpr(Val.get(), Val.get()->getExprLoc(), false,
432	getLangOpts().CPlusPlus11);
433	}
434
435	StmtResult
436	Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprResult LHSVal,
437	SourceLocation DotDotDotLoc, ExprResult RHSVal,
438	SourceLocation ColonLoc) {
439	(0) . __assert_fail ("(LHSVal.isInvalid() \|\| LHSVal.get()) && \"missing LHS value\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 439, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert((LHSVal.isInvalid() \|\| LHSVal.get()) && "missing LHS value");
440	(0) . __assert_fail ("(DotDotDotLoc.isInvalid() ? RHSVal.isUnset() . RHSVal.isInvalid() \|\| RHSVal.get()) && \"missing RHS value\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 442, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert((DotDotDotLoc.isInvalid() ? RHSVal.isUnset()
441	(0) . __assert_fail ("(DotDotDotLoc.isInvalid() ? RHSVal.isUnset() . RHSVal.isInvalid() \|\| RHSVal.get()) && \"missing RHS value\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 442, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> : RHSVal.isInvalid() \|\| RHSVal.get()) &&
442	(0) . __assert_fail ("(DotDotDotLoc.isInvalid() ? RHSVal.isUnset() . RHSVal.isInvalid() \|\| RHSVal.get()) && \"missing RHS value\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 442, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "missing RHS value");
443
444	if (getCurFunction()->SwitchStack.empty()) {
445	Diag(CaseLoc, diag::err_case_not_in_switch);
446	return StmtError();
447	}
448
449	if (LHSVal.isInvalid() \|\| RHSVal.isInvalid()) {
450	getCurFunction()->SwitchStack.back().setInt(true);
451	return StmtError();
452	}
453
454	auto *CS = CaseStmt::Create(Context, LHSVal.get(), RHSVal.get(),
455	CaseLoc, DotDotDotLoc, ColonLoc);
456	getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(CS);
457	return CS;
458	}
459
460	/// ActOnCaseStmtBody - This installs a statement as the body of a case.
461	void Sema::ActOnCaseStmtBody(Stmt S, Stmt SubStmt) {
462	cast<CaseStmt>(S)->setSubStmt(SubStmt);
463	}
464
465	StmtResult
466	Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
467	Stmt SubStmt, Scope CurScope) {
468	if (getCurFunction()->SwitchStack.empty()) {
469	Diag(DefaultLoc, diag::err_default_not_in_switch);
470	return SubStmt;
471	}
472
473	DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
474	getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(DS);
475	return DS;
476	}
477
478	StmtResult
479	Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
480	SourceLocation ColonLoc, Stmt *SubStmt) {
481	// If the label was multiply defined, reject it now.
482	if (TheDecl->getStmt()) {
483	Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName();
484	Diag(TheDecl->getLocation(), diag::note_previous_definition);
485	return SubStmt;
486	}
487
488	// Otherwise, things are good. Fill in the declaration and return it.
489	LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt);
490	TheDecl->setStmt(LS);
491	if (!TheDecl->isGnuLocal()) {
492	TheDecl->setLocStart(IdentLoc);
493	if (!TheDecl->isMSAsmLabel()) {
494	// Don't update the location of MS ASM labels. These will result in
495	// a diagnostic, and changing the location here will mess that up.
496	TheDecl->setLocation(IdentLoc);
497	}
498	}
499	return LS;
500	}
501
502	StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc,
503	ArrayRef<const Attr*> Attrs,
504	Stmt *SubStmt) {
505	// Fill in the declaration and return it.
506	AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt);
507	return LS;
508	}
509
510	namespace {
511	class CommaVisitor : public EvaluatedExprVisitor<CommaVisitor> {
512	typedef EvaluatedExprVisitor<CommaVisitor> Inherited;
513	Sema &SemaRef;
514	public:
515	CommaVisitor(Sema &SemaRef) : Inherited(SemaRef.Context), SemaRef(SemaRef) {}
516	void VisitBinaryOperator(BinaryOperator *E) {
517	if (E->getOpcode() == BO_Comma)
518	SemaRef.DiagnoseCommaOperator(E->getLHS(), E->getExprLoc());
519	EvaluatedExprVisitor<CommaVisitor>::VisitBinaryOperator(E);
520	}
521	};
522	}
523
524	StmtResult
525	Sema::ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr, Stmt *InitStmt,
526	ConditionResult Cond,
527	Stmt *thenStmt, SourceLocation ElseLoc,
528	Stmt *elseStmt) {
529	if (Cond.isInvalid())
530	Cond = ConditionResult(
531	*this, nullptr,
532	MakeFullExpr(new (Context) OpaqueValueExpr(SourceLocation(),
533	Context.BoolTy, VK_RValue),
534	IfLoc),
535	false);
536
537	Expr *CondExpr = Cond.get().second;
538	// Only call the CommaVisitor when not C89 due to differences in scope flags.
539	if ((getLangOpts().C99 \|\| getLangOpts().CPlusPlus) &&
540	!Diags.isIgnored(diag::warn_comma_operator, CondExpr->getExprLoc()))
541	CommaVisitor(*this).Visit(CondExpr);
542
543	if (!elseStmt)
544	DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), thenStmt,
545	diag::warn_empty_if_body);
546
547	return BuildIfStmt(IfLoc, IsConstexpr, InitStmt, Cond, thenStmt, ElseLoc,
548	elseStmt);
549	}
550
551	StmtResult Sema::BuildIfStmt(SourceLocation IfLoc, bool IsConstexpr,
552	Stmt *InitStmt, ConditionResult Cond,
553	Stmt *thenStmt, SourceLocation ElseLoc,
554	Stmt *elseStmt) {
555	if (Cond.isInvalid())
556	return StmtError();
557
558	if (IsConstexpr \|\| isa<ObjCAvailabilityCheckExpr>(Cond.get().second))
559	setFunctionHasBranchProtectedScope();
560
561	return IfStmt::Create(Context, IfLoc, IsConstexpr, InitStmt, Cond.get().first,
562	Cond.get().second, thenStmt, ElseLoc, elseStmt);
563	}
564
565	namespace {
566	struct CaseCompareFunctor {
567	bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
568	const llvm::APSInt &RHS) {
569	return LHS.first < RHS;
570	}
571	bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
572	const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
573	return LHS.first < RHS.first;
574	}
575	bool operator()(const llvm::APSInt &LHS,
576	const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
577	return LHS < RHS.first;
578	}
579	};
580	}
581
582	/// CmpCaseVals - Comparison predicate for sorting case values.
583	///
584	static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
585	const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
586	if (lhs.first < rhs.first)
587	return true;
588
589	if (lhs.first == rhs.first &&
590	lhs.second->getCaseLoc().getRawEncoding()
591	< rhs.second->getCaseLoc().getRawEncoding())
592	return true;
593	return false;
594	}
595
596	/// CmpEnumVals - Comparison predicate for sorting enumeration values.
597	///
598	static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
599	const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
600	{
601	return lhs.first < rhs.first;
602	}
603
604	/// EqEnumVals - Comparison preficate for uniqing enumeration values.
605	///
606	static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
607	const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
608	{
609	return lhs.first == rhs.first;
610	}
611
612	/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of
613	/// potentially integral-promoted expression @p expr.
614	static QualType GetTypeBeforeIntegralPromotion(const Expr *&E) {
615	if (const auto *FE = dyn_cast<FullExpr>(E))
616	E = FE->getSubExpr();
617	while (const auto *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
618	if (ImpCast->getCastKind() != CK_IntegralCast) break;
619	E = ImpCast->getSubExpr();
620	}
621	return E->getType();
622	}
623
624	ExprResult Sema::CheckSwitchCondition(SourceLocation SwitchLoc, Expr *Cond) {
625	class SwitchConvertDiagnoser : public ICEConvertDiagnoser {
626	Expr *Cond;
627
628	public:
629	SwitchConvertDiagnoser(Expr *Cond)
630	: ICEConvertDiagnoser(/AllowScopedEnumerations/true, false, true),
631	Cond(Cond) {}
632
633	SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
634	QualType T) override {
635	return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T;
636	}
637
638	SemaDiagnosticBuilder diagnoseIncomplete(
639	Sema &S, SourceLocation Loc, QualType T) override {
640	return S.Diag(Loc, diag::err_switch_incomplete_class_type)
641	<< T << Cond->getSourceRange();
642	}
643
644	SemaDiagnosticBuilder diagnoseExplicitConv(
645	Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
646	return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy;
647	}
648
649	SemaDiagnosticBuilder noteExplicitConv(
650	Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
651	return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
652	<< ConvTy->isEnumeralType() << ConvTy;
653	}
654
655	SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
656	QualType T) override {
657	return S.Diag(Loc, diag::err_switch_multiple_conversions) << T;
658	}
659
660	SemaDiagnosticBuilder noteAmbiguous(
661	Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
662	return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
663	<< ConvTy->isEnumeralType() << ConvTy;
664	}
665
666	SemaDiagnosticBuilder diagnoseConversion(
667	Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
668	llvm_unreachable("conversion functions are permitted");
669	}
670	} SwitchDiagnoser(Cond);
671
672	ExprResult CondResult =
673	PerformContextualImplicitConversion(SwitchLoc, Cond, SwitchDiagnoser);
674	if (CondResult.isInvalid())
675	return ExprError();
676
677	// FIXME: PerformContextualImplicitConversion doesn't always tell us if it
678	// failed and produced a diagnostic.
679	Cond = CondResult.get();
680	if (!Cond->isTypeDependent() &&
681	!Cond->getType()->isIntegralOrEnumerationType())
682	return ExprError();
683
684	// C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
685	return UsualUnaryConversions(Cond);
686	}
687
688	StmtResult Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc,
689	Stmt *InitStmt, ConditionResult Cond) {
690	Expr *CondExpr = Cond.get().second;
691	(0) . __assert_fail ("(Cond.isInvalid() \|\| CondExpr) && \"switch with no condition\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 691, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert((Cond.isInvalid() \|\| CondExpr) && "switch with no condition");
692
693	if (CondExpr && !CondExpr->isTypeDependent()) {
694	// We have already converted the expression to an integral or enumeration
695	// type, when we parsed the switch condition. If we don't have an
696	// appropriate type now, enter the switch scope but remember that it's
697	// invalid.
698	(0) . __assert_fail ("CondExpr->getType()->isIntegralOrEnumerationType() && \"invalid condition type\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 699, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(CondExpr->getType()->isIntegralOrEnumerationType() &&
699	(0) . __assert_fail ("CondExpr->getType()->isIntegralOrEnumerationType() && \"invalid condition type\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 699, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "invalid condition type");
700	if (CondExpr->isKnownToHaveBooleanValue()) {
701	// switch(bool_expr) {...} is often a programmer error, e.g.
702	// switch(n && mask) { ... } // Doh - should be "n & mask".
703	// One can always use an if statement instead of switch(bool_expr).
704	Diag(SwitchLoc, diag::warn_bool_switch_condition)
705	<< CondExpr->getSourceRange();
706	}
707	}
708
709	setFunctionHasBranchIntoScope();
710
711	auto *SS = SwitchStmt::Create(Context, InitStmt, Cond.get().first, CondExpr);
712	getCurFunction()->SwitchStack.push_back(
713	FunctionScopeInfo::SwitchInfo(SS, false));
714	return SS;
715	}
716
717	static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) {
718	Val = Val.extOrTrunc(BitWidth);
719	Val.setIsSigned(IsSigned);
720	}
721
722	/// Check the specified case value is in range for the given unpromoted switch
723	/// type.
724	static void checkCaseValue(Sema &S, SourceLocation Loc, const llvm::APSInt &Val,
725	unsigned UnpromotedWidth, bool UnpromotedSign) {
726	// In C++11 onwards, this is checked by the language rules.
727	if (S.getLangOpts().CPlusPlus11)
728	return;
729
730	// If the case value was signed and negative and the switch expression is
731	// unsigned, don't bother to warn: this is implementation-defined behavior.
732	// FIXME: Introduce a second, default-ignored warning for this case?
733	if (UnpromotedWidth < Val.getBitWidth()) {
734	llvm::APSInt ConvVal(Val);
735	AdjustAPSInt(ConvVal, UnpromotedWidth, UnpromotedSign);
736	AdjustAPSInt(ConvVal, Val.getBitWidth(), Val.isSigned());
737	// FIXME: Use different diagnostics for overflow in conversion to promoted
738	// type versus "switch expression cannot have this value". Use proper
739	// IntRange checking rather than just looking at the unpromoted type here.
740	if (ConvVal != Val)
741	S.Diag(Loc, diag::warn_case_value_overflow) << Val.toString(10)
742	<< ConvVal.toString(10);
743	}
744	}
745
746	typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> EnumValsTy;
747
748	/// Returns true if we should emit a diagnostic about this case expression not
749	/// being a part of the enum used in the switch controlling expression.
750	static bool ShouldDiagnoseSwitchCaseNotInEnum(const Sema &S,
751	const EnumDecl *ED,
752	const Expr *CaseExpr,
753	EnumValsTy::iterator &EI,
754	EnumValsTy::iterator &EIEnd,
755	const llvm::APSInt &Val) {
756	if (!ED->isClosed())
757	return false;
758
759	if (const DeclRefExpr *DRE =
760	dyn_cast<DeclRefExpr>(CaseExpr->IgnoreParenImpCasts())) {
761	if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
762	QualType VarType = VD->getType();
763	QualType EnumType = S.Context.getTypeDeclType(ED);
764	if (VD->hasGlobalStorage() && VarType.isConstQualified() &&
765	S.Context.hasSameUnqualifiedType(EnumType, VarType))
766	return false;
767	}
768	}
769
770	if (ED->hasAttr<FlagEnumAttr>())
771	return !S.IsValueInFlagEnum(ED, Val, false);
772
773	while (EI != EIEnd && EI->first < Val)
774	EI++;
775
776	if (EI != EIEnd && EI->first == Val)
777	return false;
778
779	return true;
780	}
781
782	static void checkEnumTypesInSwitchStmt(Sema &S, const Expr *Cond,
783	const Expr *Case) {
784	QualType CondType = Cond->getType();
785	QualType CaseType = Case->getType();
786
787	const EnumType *CondEnumType = CondType->getAs<EnumType>();
788	const EnumType *CaseEnumType = CaseType->getAs<EnumType>();
789	if (!CondEnumType \|\| !CaseEnumType)
790	return;
791
792	// Ignore anonymous enums.
793	if (!CondEnumType->getDecl()->getIdentifier() &&
794	!CondEnumType->getDecl()->getTypedefNameForAnonDecl())
795	return;
796	if (!CaseEnumType->getDecl()->getIdentifier() &&
797	!CaseEnumType->getDecl()->getTypedefNameForAnonDecl())
798	return;
799
800	if (S.Context.hasSameUnqualifiedType(CondType, CaseType))
801	return;
802
803	S.Diag(Case->getExprLoc(), diag::warn_comparison_of_mixed_enum_types_switch)
804	<< CondType << CaseType << Cond->getSourceRange()
805	<< Case->getSourceRange();
806	}
807
808	StmtResult
809	Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
810	Stmt *BodyStmt) {
811	SwitchStmt *SS = cast<SwitchStmt>(Switch);
812	bool CaseListIsIncomplete = getCurFunction()->SwitchStack.back().getInt();
813	(0) . __assert_fail ("SS == getCurFunction()->SwitchStack.back().getPointer() && \"switch stack missing push/pop!\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 814, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(SS == getCurFunction()->SwitchStack.back().getPointer() &&
814	(0) . __assert_fail ("SS == getCurFunction()->SwitchStack.back().getPointer() && \"switch stack missing push/pop!\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 814, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "switch stack missing push/pop!");
815
816	getCurFunction()->SwitchStack.pop_back();
817
818	if (!BodyStmt) return StmtError();
819	SS->setBody(BodyStmt, SwitchLoc);
820
821	Expr *CondExpr = SS->getCond();
822	if (!CondExpr) return StmtError();
823
824	QualType CondType = CondExpr->getType();
825
826	// C++ 6.4.2.p2:
827	// Integral promotions are performed (on the switch condition).
828	//
829	// A case value unrepresentable by the original switch condition
830	// type (before the promotion) doesn't make sense, even when it can
831	// be represented by the promoted type. Therefore we need to find
832	// the pre-promotion type of the switch condition.
833	const Expr *CondExprBeforePromotion = CondExpr;
834	QualType CondTypeBeforePromotion =
835	GetTypeBeforeIntegralPromotion(CondExprBeforePromotion);
836
837	// Get the bitwidth of the switched-on value after promotions. We must
838	// convert the integer case values to this width before comparison.
839	bool HasDependentValue
840	= CondExpr->isTypeDependent() \|\| CondExpr->isValueDependent();
841	unsigned CondWidth = HasDependentValue ? 0 : Context.getIntWidth(CondType);
842	bool CondIsSigned = CondType->isSignedIntegerOrEnumerationType();
843
844	// Get the width and signedness that the condition might actually have, for
845	// warning purposes.
846	// FIXME: Grab an IntRange for the condition rather than using the unpromoted
847	// type.
848	unsigned CondWidthBeforePromotion
849	= HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion);
850	bool CondIsSignedBeforePromotion
851	= CondTypeBeforePromotion->isSignedIntegerOrEnumerationType();
852
853	// Accumulate all of the case values in a vector so that we can sort them
854	// and detect duplicates. This vector contains the APInt for the case after
855	// it has been converted to the condition type.
856	typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
857	CaseValsTy CaseVals;
858
859	// Keep track of any GNU case ranges we see. The APSInt is the low value.
860	typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy;
861	CaseRangesTy CaseRanges;
862
863	DefaultStmt *TheDefaultStmt = nullptr;
864
865	bool CaseListIsErroneous = false;
866
867	for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
868	SC = SC->getNextSwitchCase()) {
869
870	if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
871	if (TheDefaultStmt) {
872	Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
873	Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
874
875	// FIXME: Remove the default statement from the switch block so that
876	// we'll return a valid AST. This requires recursing down the AST and
877	// finding it, not something we are set up to do right now. For now,
878	// just lop the entire switch stmt out of the AST.
879	CaseListIsErroneous = true;
880	}
881	TheDefaultStmt = DS;
882
883	} else {
884	CaseStmt *CS = cast<CaseStmt>(SC);
885
886	Expr *Lo = CS->getLHS();
887
888	if (Lo->isValueDependent()) {
889	HasDependentValue = true;
890	break;
891	}
892
893	// We already verified that the expression has a constant value;
894	// get that value (prior to conversions).
895	const Expr *LoBeforePromotion = Lo;
896	GetTypeBeforeIntegralPromotion(LoBeforePromotion);
897	llvm::APSInt LoVal = LoBeforePromotion->EvaluateKnownConstInt(Context);
898
899	// Check the unconverted value is within the range of possible values of
900	// the switch expression.
901	checkCaseValue(*this, Lo->getBeginLoc(), LoVal, CondWidthBeforePromotion,
902	CondIsSignedBeforePromotion);
903
904	// FIXME: This duplicates the check performed for warn_not_in_enum below.
905	checkEnumTypesInSwitchStmt(*this, CondExprBeforePromotion,
906	LoBeforePromotion);
907
908	// Convert the value to the same width/sign as the condition.
909	AdjustAPSInt(LoVal, CondWidth, CondIsSigned);
910
911	// If this is a case range, remember it in CaseRanges, otherwise CaseVals.
912	if (CS->getRHS()) {
913	if (CS->getRHS()->isValueDependent()) {
914	HasDependentValue = true;
915	break;
916	}
917	CaseRanges.push_back(std::make_pair(LoVal, CS));
918	} else
919	CaseVals.push_back(std::make_pair(LoVal, CS));
920	}
921	}
922
923	if (!HasDependentValue) {
924	// If we don't have a default statement, check whether the
925	// condition is constant.
926	llvm::APSInt ConstantCondValue;
927	bool HasConstantCond = false;
928	if (!HasDependentValue && !TheDefaultStmt) {
929	Expr::EvalResult Result;
930	HasConstantCond = CondExpr->EvaluateAsInt(Result, Context,
931	Expr::SE_AllowSideEffects);
932	if (Result.Val.isInt())
933	ConstantCondValue = Result.Val.getInt();
934	assert(!HasConstantCond \|\|
935	(ConstantCondValue.getBitWidth() == CondWidth &&
936	ConstantCondValue.isSigned() == CondIsSigned));
937	}
938	bool ShouldCheckConstantCond = HasConstantCond;
939
940	// Sort all the scalar case values so we can easily detect duplicates.
941	std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals);
942
943	if (!CaseVals.empty()) {
944	for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) {
945	if (ShouldCheckConstantCond &&
946	CaseVals[i].first == ConstantCondValue)
947	ShouldCheckConstantCond = false;
948
949	if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) {
950	// If we have a duplicate, report it.
951	// First, determine if either case value has a name
952	StringRef PrevString, CurrString;
953	Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts();
954	Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts();
955	if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) {
956	PrevString = DeclRef->getDecl()->getName();
957	}
958	if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) {
959	CurrString = DeclRef->getDecl()->getName();
960	}
961	SmallString<16> CaseValStr;
962	CaseVals[i-1].first.toString(CaseValStr);
963
964	if (PrevString == CurrString)
965	Diag(CaseVals[i].second->getLHS()->getBeginLoc(),
966	diag::err_duplicate_case)
967	<< (PrevString.empty() ? StringRef(CaseValStr) : PrevString);
968	else
969	Diag(CaseVals[i].second->getLHS()->getBeginLoc(),
970	diag::err_duplicate_case_differing_expr)
971	<< (PrevString.empty() ? StringRef(CaseValStr) : PrevString)
972	<< (CurrString.empty() ? StringRef(CaseValStr) : CurrString)
973	<< CaseValStr;
974
975	Diag(CaseVals[i - 1].second->getLHS()->getBeginLoc(),
976	diag::note_duplicate_case_prev);
977	// FIXME: We really want to remove the bogus case stmt from the
978	// substmt, but we have no way to do this right now.
979	CaseListIsErroneous = true;
980	}
981	}
982	}
983
984	// Detect duplicate case ranges, which usually don't exist at all in
985	// the first place.
986	if (!CaseRanges.empty()) {
987	// Sort all the case ranges by their low value so we can easily detect
988	// overlaps between ranges.
989	std::stable_sort(CaseRanges.begin(), CaseRanges.end());
990
991	// Scan the ranges, computing the high values and removing empty ranges.
992	std::vector<llvm::APSInt> HiVals;
993	for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
994	llvm::APSInt &LoVal = CaseRanges[i].first;
995	CaseStmt *CR = CaseRanges[i].second;
996	Expr *Hi = CR->getRHS();
997
998	const Expr *HiBeforePromotion = Hi;
999	GetTypeBeforeIntegralPromotion(HiBeforePromotion);
1000	llvm::APSInt HiVal = HiBeforePromotion->EvaluateKnownConstInt(Context);
1001
1002	// Check the unconverted value is within the range of possible values of
1003	// the switch expression.
1004	checkCaseValue(*this, Hi->getBeginLoc(), HiVal,
1005	CondWidthBeforePromotion, CondIsSignedBeforePromotion);
1006
1007	// Convert the value to the same width/sign as the condition.
1008	AdjustAPSInt(HiVal, CondWidth, CondIsSigned);
1009
1010	// If the low value is bigger than the high value, the case is empty.
1011	if (LoVal > HiVal) {
1012	Diag(CR->getLHS()->getBeginLoc(), diag::warn_case_empty_range)
1013	<< SourceRange(CR->getLHS()->getBeginLoc(), Hi->getEndLoc());
1014	CaseRanges.erase(CaseRanges.begin()+i);
1015	--i;
1016	--e;
1017	continue;
1018	}
1019
1020	if (ShouldCheckConstantCond &&
1021	LoVal <= ConstantCondValue &&
1022	ConstantCondValue <= HiVal)
1023	ShouldCheckConstantCond = false;
1024
1025	HiVals.push_back(HiVal);
1026	}
1027
1028	// Rescan the ranges, looking for overlap with singleton values and other
1029	// ranges. Since the range list is sorted, we only need to compare case
1030	// ranges with their neighbors.
1031	for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
1032	llvm::APSInt &CRLo = CaseRanges[i].first;
1033	llvm::APSInt &CRHi = HiVals[i];
1034	CaseStmt *CR = CaseRanges[i].second;
1035
1036	// Check to see whether the case range overlaps with any
1037	// singleton cases.
1038	CaseStmt *OverlapStmt = nullptr;
1039	llvm::APSInt OverlapVal(32);
1040
1041	// Find the smallest value >= the lower bound. If I is in the
1042	// case range, then we have overlap.
1043	CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(),
1044	CaseVals.end(), CRLo,
1045	CaseCompareFunctor());
1046	if (I != CaseVals.end() && I->first < CRHi) {
1047	OverlapVal = I->first; // Found overlap with scalar.
1048	OverlapStmt = I->second;
1049	}
1050
1051	// Find the smallest value bigger than the upper bound.
1052	I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
1053	if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
1054	OverlapVal = (I-1)->first; // Found overlap with scalar.
1055	OverlapStmt = (I-1)->second;
1056	}
1057
1058	// Check to see if this case stmt overlaps with the subsequent
1059	// case range.
1060	if (i && CRLo <= HiVals[i-1]) {
1061	OverlapVal = HiVals[i-1]; // Found overlap with range.
1062	OverlapStmt = CaseRanges[i-1].second;
1063	}
1064
1065	if (OverlapStmt) {
1066	// If we have a duplicate, report it.
1067	Diag(CR->getLHS()->getBeginLoc(), diag::err_duplicate_case)
1068	<< OverlapVal.toString(10);
1069	Diag(OverlapStmt->getLHS()->getBeginLoc(),
1070	diag::note_duplicate_case_prev);
1071	// FIXME: We really want to remove the bogus case stmt from the
1072	// substmt, but we have no way to do this right now.
1073	CaseListIsErroneous = true;
1074	}
1075	}
1076	}
1077
1078	// Complain if we have a constant condition and we didn't find a match.
1079	if (!CaseListIsErroneous && !CaseListIsIncomplete &&
1080	ShouldCheckConstantCond) {
1081	// TODO: it would be nice if we printed enums as enums, chars as
1082	// chars, etc.
1083	Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition)
1084	<< ConstantCondValue.toString(10)
1085	<< CondExpr->getSourceRange();
1086	}
1087
1088	// Check to see if switch is over an Enum and handles all of its
1089	// values. We only issue a warning if there is not 'default:', but
1090	// we still do the analysis to preserve this information in the AST
1091	// (which can be used by flow-based analyes).
1092	//
1093	const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>();
1094
1095	// If switch has default case, then ignore it.
1096	if (!CaseListIsErroneous && !CaseListIsIncomplete && !HasConstantCond &&
1097	ET && ET->getDecl()->isCompleteDefinition()) {
1098	const EnumDecl *ED = ET->getDecl();
1099	EnumValsTy EnumVals;
1100
1101	// Gather all enum values, set their type and sort them,
1102	// allowing easier comparison with CaseVals.
1103	for (auto *EDI : ED->enumerators()) {
1104	llvm::APSInt Val = EDI->getInitVal();
1105	AdjustAPSInt(Val, CondWidth, CondIsSigned);
1106	EnumVals.push_back(std::make_pair(Val, EDI));
1107	}
1108	std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
1109	auto EI = EnumVals.begin(), EIEnd =
1110	std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
1111
1112	// See which case values aren't in enum.
1113	for (CaseValsTy::const_iterator CI = CaseVals.begin();
1114	CI != CaseVals.end(); CI++) {
1115	Expr *CaseExpr = CI->second->getLHS();
1116	if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1117	CI->first))
1118	Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1119	<< CondTypeBeforePromotion;
1120	}
1121
1122	// See which of case ranges aren't in enum
1123	EI = EnumVals.begin();
1124	for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
1125	RI != CaseRanges.end(); RI++) {
1126	Expr *CaseExpr = RI->second->getLHS();
1127	if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1128	RI->first))
1129	Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1130	<< CondTypeBeforePromotion;
1131
1132	llvm::APSInt Hi =
1133	RI->second->getRHS()->EvaluateKnownConstInt(Context);
1134	AdjustAPSInt(Hi, CondWidth, CondIsSigned);
1135
1136	CaseExpr = RI->second->getRHS();
1137	if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1138	Hi))
1139	Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1140	<< CondTypeBeforePromotion;
1141	}
1142
1143	// Check which enum vals aren't in switch
1144	auto CI = CaseVals.begin();
1145	auto RI = CaseRanges.begin();
1146	bool hasCasesNotInSwitch = false;
1147
1148	SmallVector<DeclarationName,8> UnhandledNames;
1149
1150	for (EI = EnumVals.begin(); EI != EIEnd; EI++) {
1151	// Don't warn about omitted unavailable EnumConstantDecls.
1152	switch (EI->second->getAvailability()) {
1153	case AR_Deprecated:
1154	// Omitting a deprecated constant is ok; it should never materialize.
1155	case AR_Unavailable:
1156	continue;
1157
1158	case AR_NotYetIntroduced:
1159	// Partially available enum constants should be present. Note that we
1160	// suppress -Wunguarded-availability diagnostics for such uses.
1161	case AR_Available:
1162	break;
1163	}
1164
1165	// Drop unneeded case values
1166	while (CI != CaseVals.end() && CI->first < EI->first)
1167	CI++;
1168
1169	if (CI != CaseVals.end() && CI->first == EI->first)
1170	continue;
1171
1172	// Drop unneeded case ranges
1173	for (; RI != CaseRanges.end(); RI++) {
1174	llvm::APSInt Hi =
1175	RI->second->getRHS()->EvaluateKnownConstInt(Context);
1176	AdjustAPSInt(Hi, CondWidth, CondIsSigned);
1177	if (EI->first <= Hi)
1178	break;
1179	}
1180
1181	if (RI == CaseRanges.end() \|\| EI->first < RI->first) {
1182	hasCasesNotInSwitch = true;
1183	UnhandledNames.push_back(EI->second->getDeclName());
1184	}
1185	}
1186
1187	if (TheDefaultStmt && UnhandledNames.empty() && ED->isClosedNonFlag())
1188	Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default);
1189
1190	// Produce a nice diagnostic if multiple values aren't handled.
1191	if (!UnhandledNames.empty()) {
1192	DiagnosticBuilder DB = Diag(CondExpr->getExprLoc(),
1193	TheDefaultStmt ? diag::warn_def_missing_case
1194	: diag::warn_missing_case)
1195	<< (int)UnhandledNames.size();
1196
1197	for (size_t I = 0, E = std::min(UnhandledNames.size(), (size_t)3);
1198	I != E; ++I)
1199	DB << UnhandledNames[I];
1200	}
1201
1202	if (!hasCasesNotInSwitch)
1203	SS->setAllEnumCasesCovered();
1204	}
1205	}
1206
1207	if (BodyStmt)
1208	DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), BodyStmt,
1209	diag::warn_empty_switch_body);
1210
1211	// FIXME: If the case list was broken is some way, we don't have a good system
1212	// to patch it up. Instead, just return the whole substmt as broken.
1213	if (CaseListIsErroneous)
1214	return StmtError();
1215
1216	return SS;
1217	}
1218
1219	void
1220	Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType,
1221	Expr *SrcExpr) {
1222	if (Diags.isIgnored(diag::warn_not_in_enum_assignment, SrcExpr->getExprLoc()))
1223	return;
1224
1225	if (const EnumType *ET = DstType->getAs<EnumType>())
1226	if (!Context.hasSameUnqualifiedType(SrcType, DstType) &&
1227	SrcType->isIntegerType()) {
1228	if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() &&
1229	SrcExpr->isIntegerConstantExpr(Context)) {
1230	// Get the bitwidth of the enum value before promotions.
1231	unsigned DstWidth = Context.getIntWidth(DstType);
1232	bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType();
1233
1234	llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context);
1235	AdjustAPSInt(RhsVal, DstWidth, DstIsSigned);
1236	const EnumDecl *ED = ET->getDecl();
1237
1238	if (!ED->isClosed())
1239	return;
1240
1241	if (ED->hasAttr<FlagEnumAttr>()) {
1242	if (!IsValueInFlagEnum(ED, RhsVal, true))
1243	Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
1244	<< DstType.getUnqualifiedType();
1245	} else {
1246	typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl *>, 64>
1247	EnumValsTy;
1248	EnumValsTy EnumVals;
1249
1250	// Gather all enum values, set their type and sort them,
1251	// allowing easier comparison with rhs constant.
1252	for (auto *EDI : ED->enumerators()) {
1253	llvm::APSInt Val = EDI->getInitVal();
1254	AdjustAPSInt(Val, DstWidth, DstIsSigned);
1255	EnumVals.push_back(std::make_pair(Val, EDI));
1256	}
1257	if (EnumVals.empty())
1258	return;
1259	std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
1260	EnumValsTy::iterator EIend =
1261	std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
1262
1263	// See which values aren't in the enum.
1264	EnumValsTy::const_iterator EI = EnumVals.begin();
1265	while (EI != EIend && EI->first < RhsVal)
1266	EI++;
1267	if (EI == EIend \|\| EI->first != RhsVal) {
1268	Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
1269	<< DstType.getUnqualifiedType();
1270	}
1271	}
1272	}
1273	}
1274	}
1275
1276	StmtResult Sema::ActOnWhileStmt(SourceLocation WhileLoc, ConditionResult Cond,
1277	Stmt *Body) {
1278	if (Cond.isInvalid())
1279	return StmtError();
1280
1281	auto CondVal = Cond.get();
1282	CheckBreakContinueBinding(CondVal.second);
1283
1284	if (CondVal.second &&
1285	!Diags.isIgnored(diag::warn_comma_operator, CondVal.second->getExprLoc()))
1286	CommaVisitor(*this).Visit(CondVal.second);
1287
1288	if (isa<NullStmt>(Body))
1289	getCurCompoundScope().setHasEmptyLoopBodies();
1290
1291	return WhileStmt::Create(Context, CondVal.first, CondVal.second, Body,
1292	WhileLoc);
1293	}
1294
1295	StmtResult
1296	Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
1297	SourceLocation WhileLoc, SourceLocation CondLParen,
1298	Expr *Cond, SourceLocation CondRParen) {
1299	(0) . __assert_fail ("Cond && \"ActOnDoStmt(). missing expression\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 1299, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Cond && "ActOnDoStmt(): missing expression");
1300
1301	CheckBreakContinueBinding(Cond);
1302	ExprResult CondResult = CheckBooleanCondition(DoLoc, Cond);
1303	if (CondResult.isInvalid())
1304	return StmtError();
1305	Cond = CondResult.get();
1306
1307	CondResult = ActOnFinishFullExpr(Cond, DoLoc, /DiscardedValue/ false);
1308	if (CondResult.isInvalid())
1309	return StmtError();
1310	Cond = CondResult.get();
1311
1312	// Only call the CommaVisitor for C89 due to differences in scope flags.
1313	if (Cond && !getLangOpts().C99 && !getLangOpts().CPlusPlus &&
1314	!Diags.isIgnored(diag::warn_comma_operator, Cond->getExprLoc()))
1315	CommaVisitor(*this).Visit(Cond);
1316
1317	return new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen);
1318	}
1319
1320	namespace {
1321	// Use SetVector since the diagnostic cares about the ordering of the Decl's.
1322	using DeclSetVector =
1323	llvm::SetVector<VarDecl , llvm::SmallVector<VarDecl , 8>,
1324	llvm::SmallPtrSet<VarDecl *, 8>>;
1325
1326	// This visitor will traverse a conditional statement and store all
1327	// the evaluated decls into a vector. Simple is set to true if none
1328	// of the excluded constructs are used.
1329	class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> {
1330	DeclSetVector &Decls;
1331	SmallVectorImpl<SourceRange> &Ranges;
1332	bool Simple;
1333	public:
1334	typedef EvaluatedExprVisitor<DeclExtractor> Inherited;
1335
1336	DeclExtractor(Sema &S, DeclSetVector &Decls,
1337	SmallVectorImpl<SourceRange> &Ranges) :
1338	Inherited(S.Context),
1339	Decls(Decls),
1340	Ranges(Ranges),
1341	Simple(true) {}
1342
1343	bool isSimple() { return Simple; }
1344
1345	// Replaces the method in EvaluatedExprVisitor.
1346	void VisitMemberExpr(MemberExpr* E) {
1347	Simple = false;
1348	}
1349
1350	// Any Stmt not whitelisted will cause the condition to be marked complex.
1351	void VisitStmt(Stmt *S) {
1352	Simple = false;
1353	}
1354
1355	void VisitBinaryOperator(BinaryOperator *E) {
1356	Visit(E->getLHS());
1357	Visit(E->getRHS());
1358	}
1359
1360	void VisitCastExpr(CastExpr *E) {
1361	Visit(E->getSubExpr());
1362	}
1363
1364	void VisitUnaryOperator(UnaryOperator *E) {
1365	// Skip checking conditionals with derefernces.
1366	if (E->getOpcode() == UO_Deref)
1367	Simple = false;
1368	else
1369	Visit(E->getSubExpr());
1370	}
1371
1372	void VisitConditionalOperator(ConditionalOperator *E) {
1373	Visit(E->getCond());
1374	Visit(E->getTrueExpr());
1375	Visit(E->getFalseExpr());
1376	}
1377
1378	void VisitParenExpr(ParenExpr *E) {
1379	Visit(E->getSubExpr());
1380	}
1381
1382	void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
1383	Visit(E->getOpaqueValue()->getSourceExpr());
1384	Visit(E->getFalseExpr());
1385	}
1386
1387	void VisitIntegerLiteral(IntegerLiteral *E) { }
1388	void VisitFloatingLiteral(FloatingLiteral *E) { }
1389	void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { }
1390	void VisitCharacterLiteral(CharacterLiteral *E) { }
1391	void VisitGNUNullExpr(GNUNullExpr *E) { }
1392	void VisitImaginaryLiteral(ImaginaryLiteral *E) { }
1393
1394	void VisitDeclRefExpr(DeclRefExpr *E) {
1395	VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
1396	if (!VD) {
1397	// Don't allow unhandled Decl types.
1398	Simple = false;
1399	return;
1400	}
1401
1402	Ranges.push_back(E->getSourceRange());
1403
1404	Decls.insert(VD);
1405	}
1406
1407	}; // end class DeclExtractor
1408
1409	// DeclMatcher checks to see if the decls are used in a non-evaluated
1410	// context.
1411	class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> {
1412	DeclSetVector &Decls;
1413	bool FoundDecl;
1414
1415	public:
1416	typedef EvaluatedExprVisitor<DeclMatcher> Inherited;
1417
1418	DeclMatcher(Sema &S, DeclSetVector &Decls, Stmt *Statement) :
1419	Inherited(S.Context), Decls(Decls), FoundDecl(false) {
1420	if (!Statement) return;
1421
1422	Visit(Statement);
1423	}
1424
1425	void VisitReturnStmt(ReturnStmt *S) {
1426	FoundDecl = true;
1427	}
1428
1429	void VisitBreakStmt(BreakStmt *S) {
1430	FoundDecl = true;
1431	}
1432
1433	void VisitGotoStmt(GotoStmt *S) {
1434	FoundDecl = true;
1435	}
1436
1437	void VisitCastExpr(CastExpr *E) {
1438	if (E->getCastKind() == CK_LValueToRValue)
1439	CheckLValueToRValueCast(E->getSubExpr());
1440	else
1441	Visit(E->getSubExpr());
1442	}
1443
1444	void CheckLValueToRValueCast(Expr *E) {
1445	E = E->IgnoreParenImpCasts();
1446
1447	if (isa<DeclRefExpr>(E)) {
1448	return;
1449	}
1450
1451	if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
1452	Visit(CO->getCond());
1453	CheckLValueToRValueCast(CO->getTrueExpr());
1454	CheckLValueToRValueCast(CO->getFalseExpr());
1455	return;
1456	}
1457
1458	if (BinaryConditionalOperator *BCO =
1459	dyn_cast<BinaryConditionalOperator>(E)) {
1460	CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr());
1461	CheckLValueToRValueCast(BCO->getFalseExpr());
1462	return;
1463	}
1464
1465	Visit(E);
1466	}
1467
1468	void VisitDeclRefExpr(DeclRefExpr *E) {
1469	if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()))
1470	if (Decls.count(VD))
1471	FoundDecl = true;
1472	}
1473
1474	void VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
1475	// Only need to visit the semantics for POE.
1476	// SyntaticForm doesn't really use the Decal.
1477	for (auto *S : POE->semantics()) {
1478	if (auto *OVE = dyn_cast<OpaqueValueExpr>(S))
1479	// Look past the OVE into the expression it binds.
1480	Visit(OVE->getSourceExpr());
1481	else
1482	Visit(S);
1483	}
1484	}
1485
1486	bool FoundDeclInUse() { return FoundDecl; }
1487
1488	}; // end class DeclMatcher
1489
1490	void CheckForLoopConditionalStatement(Sema &S, Expr *Second,
1491	Expr Third, Stmt Body) {
1492	// Condition is empty
1493	if (!Second) return;
1494
1495	if (S.Diags.isIgnored(diag::warn_variables_not_in_loop_body,
1496	Second->getBeginLoc()))
1497	return;
1498
1499	PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body);
1500	DeclSetVector Decls;
1501	SmallVector<SourceRange, 10> Ranges;
1502	DeclExtractor DE(S, Decls, Ranges);
1503	DE.Visit(Second);
1504
1505	// Don't analyze complex conditionals.
1506	if (!DE.isSimple()) return;
1507
1508	// No decls found.
1509	if (Decls.size() == 0) return;
1510
1511	// Don't warn on volatile, static, or global variables.
1512	for (auto *VD : Decls)
1513	if (VD->getType().isVolatileQualified() \|\| VD->hasGlobalStorage())
1514	return;
1515
1516	if (DeclMatcher(S, Decls, Second).FoundDeclInUse() \|\|
1517	DeclMatcher(S, Decls, Third).FoundDeclInUse() \|\|
1518	DeclMatcher(S, Decls, Body).FoundDeclInUse())
1519	return;
1520
1521	// Load decl names into diagnostic.
1522	if (Decls.size() > 4) {
1523	PDiag << 0;
1524	} else {
1525	PDiag << (unsigned)Decls.size();
1526	for (auto *VD : Decls)
1527	PDiag << VD->getDeclName();
1528	}
1529
1530	for (auto Range : Ranges)
1531	PDiag << Range;
1532
1533	S.Diag(Ranges.begin()->getBegin(), PDiag);
1534	}
1535
1536	// If Statement is an incemement or decrement, return true and sets the
1537	// variables Increment and DRE.
1538	bool ProcessIterationStmt(Sema &S, Stmt* Statement, bool &Increment,
1539	DeclRefExpr *&DRE) {
1540	if (auto Cleanups = dyn_cast<ExprWithCleanups>(Statement))
1541	if (!Cleanups->cleanupsHaveSideEffects())
1542	Statement = Cleanups->getSubExpr();
1543
1544	if (UnaryOperator *UO = dyn_cast<UnaryOperator>(Statement)) {
1545	switch (UO->getOpcode()) {
1546	default: return false;
1547	case UO_PostInc:
1548	case UO_PreInc:
1549	Increment = true;
1550	break;
1551	case UO_PostDec:
1552	case UO_PreDec:
1553	Increment = false;
1554	break;
1555	}
1556	DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr());
1557	return DRE;
1558	}
1559
1560	if (CXXOperatorCallExpr *Call = dyn_cast<CXXOperatorCallExpr>(Statement)) {
1561	FunctionDecl *FD = Call->getDirectCallee();
1562	if (!FD \|\| !FD->isOverloadedOperator()) return false;
1563	switch (FD->getOverloadedOperator()) {
1564	default: return false;
1565	case OO_PlusPlus:
1566	Increment = true;
1567	break;
1568	case OO_MinusMinus:
1569	Increment = false;
1570	break;
1571	}
1572	DRE = dyn_cast<DeclRefExpr>(Call->getArg(0));
1573	return DRE;
1574	}
1575
1576	return false;
1577	}
1578
1579	// A visitor to determine if a continue or break statement is a
1580	// subexpression.
1581	class BreakContinueFinder : public ConstEvaluatedExprVisitor<BreakContinueFinder> {
1582	SourceLocation BreakLoc;
1583	SourceLocation ContinueLoc;
1584	bool InSwitch = false;
1585
1586	public:
1587	BreakContinueFinder(Sema &S, const Stmt* Body) :
1588	Inherited(S.Context) {
1589	Visit(Body);
1590	}
1591
1592	typedef ConstEvaluatedExprVisitor<BreakContinueFinder> Inherited;
1593
1594	void VisitContinueStmt(const ContinueStmt* E) {
1595	ContinueLoc = E->getContinueLoc();
1596	}
1597
1598	void VisitBreakStmt(const BreakStmt* E) {
1599	if (!InSwitch)
1600	BreakLoc = E->getBreakLoc();
1601	}
1602
1603	void VisitSwitchStmt(const SwitchStmt* S) {
1604	if (const Stmt *Init = S->getInit())
1605	Visit(Init);
1606	if (const Stmt *CondVar = S->getConditionVariableDeclStmt())
1607	Visit(CondVar);
1608	if (const Stmt *Cond = S->getCond())
1609	Visit(Cond);
1610
1611	// Don't return break statements from the body of a switch.
1612	InSwitch = true;
1613	if (const Stmt *Body = S->getBody())
1614	Visit(Body);
1615	InSwitch = false;
1616	}
1617
1618	void VisitForStmt(const ForStmt *S) {
1619	// Only visit the init statement of a for loop; the body
1620	// has a different break/continue scope.
1621	if (const Stmt *Init = S->getInit())
1622	Visit(Init);
1623	}
1624
1625	void VisitWhileStmt(const WhileStmt *) {
1626	// Do nothing; the children of a while loop have a different
1627	// break/continue scope.
1628	}
1629
1630	void VisitDoStmt(const DoStmt *) {
1631	// Do nothing; the children of a while loop have a different
1632	// break/continue scope.
1633	}
1634
1635	void VisitCXXForRangeStmt(const CXXForRangeStmt *S) {
1636	// Only visit the initialization of a for loop; the body
1637	// has a different break/continue scope.
1638	if (const Stmt *Init = S->getInit())
1639	Visit(Init);
1640	if (const Stmt *Range = S->getRangeStmt())
1641	Visit(Range);
1642	if (const Stmt *Begin = S->getBeginStmt())
1643	Visit(Begin);
1644	if (const Stmt *End = S->getEndStmt())
1645	Visit(End);
1646	}
1647
1648	void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S) {
1649	// Only visit the initialization of a for loop; the body
1650	// has a different break/continue scope.
1651	if (const Stmt *Element = S->getElement())
1652	Visit(Element);
1653	if (const Stmt *Collection = S->getCollection())
1654	Visit(Collection);
1655	}
1656
1657	bool ContinueFound() { return ContinueLoc.isValid(); }
1658	bool BreakFound() { return BreakLoc.isValid(); }
1659	SourceLocation GetContinueLoc() { return ContinueLoc; }
1660	SourceLocation GetBreakLoc() { return BreakLoc; }
1661
1662	}; // end class BreakContinueFinder
1663
1664	// Emit a warning when a loop increment/decrement appears twice per loop
1665	// iteration. The conditions which trigger this warning are:
1666	// 1) The last statement in the loop body and the third expression in the
1667	// for loop are both increment or both decrement of the same variable
1668	// 2) No continue statements in the loop body.
1669	void CheckForRedundantIteration(Sema &S, Expr Third, Stmt Body) {
1670	// Return when there is nothing to check.
1671	if (!Body \|\| !Third) return;
1672
1673	if (S.Diags.isIgnored(diag::warn_redundant_loop_iteration,
1674	Third->getBeginLoc()))
1675	return;
1676
1677	// Get the last statement from the loop body.
1678	CompoundStmt *CS = dyn_cast<CompoundStmt>(Body);
1679	if (!CS \|\| CS->body_empty()) return;
1680	Stmt *LastStmt = CS->body_back();
1681	if (!LastStmt) return;
1682
1683	bool LoopIncrement, LastIncrement;
1684	DeclRefExpr LoopDRE, LastDRE;
1685
1686	if (!ProcessIterationStmt(S, Third, LoopIncrement, LoopDRE)) return;
1687	if (!ProcessIterationStmt(S, LastStmt, LastIncrement, LastDRE)) return;
1688
1689	// Check that the two statements are both increments or both decrements
1690	// on the same variable.
1691	if (LoopIncrement != LastIncrement \|\|
1692	LoopDRE->getDecl() != LastDRE->getDecl()) return;
1693
1694	if (BreakContinueFinder(S, Body).ContinueFound()) return;
1695
1696	S.Diag(LastDRE->getLocation(), diag::warn_redundant_loop_iteration)
1697	<< LastDRE->getDecl() << LastIncrement;
1698	S.Diag(LoopDRE->getLocation(), diag::note_loop_iteration_here)
1699	<< LoopIncrement;
1700	}
1701
1702	} // end namespace
1703
1704
1705	void Sema::CheckBreakContinueBinding(Expr *E) {
1706	if (!E \|\| getLangOpts().CPlusPlus)
1707	return;
1708	BreakContinueFinder BCFinder(*this, E);
1709	Scope *BreakParent = CurScope->getBreakParent();
1710	if (BCFinder.BreakFound() && BreakParent) {
1711	if (BreakParent->getFlags() & Scope::SwitchScope) {
1712	Diag(BCFinder.GetBreakLoc(), diag::warn_break_binds_to_switch);
1713	} else {
1714	Diag(BCFinder.GetBreakLoc(), diag::warn_loop_ctrl_binds_to_inner)
1715	<< "break";
1716	}
1717	} else if (BCFinder.ContinueFound() && CurScope->getContinueParent()) {
1718	Diag(BCFinder.GetContinueLoc(), diag::warn_loop_ctrl_binds_to_inner)
1719	<< "continue";
1720	}
1721	}
1722
1723	StmtResult Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
1724	Stmt *First, ConditionResult Second,
1725	FullExprArg third, SourceLocation RParenLoc,
1726	Stmt *Body) {
1727	if (Second.isInvalid())
1728	return StmtError();
1729
1730	if (!getLangOpts().CPlusPlus) {
1731	if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
1732	// C99 6.8.5p3: The declaration part of a 'for' statement shall only
1733	// declare identifiers for objects having storage class 'auto' or
1734	// 'register'.
1735	for (auto *DI : DS->decls()) {
1736	VarDecl *VD = dyn_cast<VarDecl>(DI);
1737	if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage())
1738	VD = nullptr;
1739	if (!VD) {
1740	Diag(DI->getLocation(), diag::err_non_local_variable_decl_in_for);
1741	DI->setInvalidDecl();
1742	}
1743	}
1744	}
1745	}
1746
1747	CheckBreakContinueBinding(Second.get().second);
1748	CheckBreakContinueBinding(third.get());
1749
1750	if (!Second.get().first)
1751	CheckForLoopConditionalStatement(*this, Second.get().second, third.get(),
1752	Body);
1753	CheckForRedundantIteration(*this, third.get(), Body);
1754
1755	if (Second.get().second &&
1756	!Diags.isIgnored(diag::warn_comma_operator,
1757	Second.get().second->getExprLoc()))
1758	CommaVisitor(*this).Visit(Second.get().second);
1759
1760	Expr *Third = third.release().getAs<Expr>();
1761	if (isa<NullStmt>(Body))
1762	getCurCompoundScope().setHasEmptyLoopBodies();
1763
1764	return new (Context)
1765	ForStmt(Context, First, Second.get().second, Second.get().first, Third,
1766	Body, ForLoc, LParenLoc, RParenLoc);
1767	}
1768
1769	/// In an Objective C collection iteration statement:
1770	/// for (x in y)
1771	/// x can be an arbitrary l-value expression. Bind it up as a
1772	/// full-expression.
1773	StmtResult Sema::ActOnForEachLValueExpr(Expr *E) {
1774	// Reduce placeholder expressions here. Note that this rejects the
1775	// use of pseudo-object l-values in this position.
1776	ExprResult result = CheckPlaceholderExpr(E);
1777	if (result.isInvalid()) return StmtError();
1778	E = result.get();
1779
1780	ExprResult FullExpr = ActOnFinishFullExpr(E, /DiscardedValue/ false);
1781	if (FullExpr.isInvalid())
1782	return StmtError();
1783	return StmtResult(static_cast<Stmt*>(FullExpr.get()));
1784	}
1785
1786	ExprResult
1787	Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) {
1788	if (!collection)
1789	return ExprError();
1790
1791	ExprResult result = CorrectDelayedTyposInExpr(collection);
1792	if (!result.isUsable())
1793	return ExprError();
1794	collection = result.get();
1795
1796	// Bail out early if we've got a type-dependent expression.
1797	if (collection->isTypeDependent()) return collection;
1798
1799	// Perform normal l-value conversion.
1800	result = DefaultFunctionArrayLvalueConversion(collection);
1801	if (result.isInvalid())
1802	return ExprError();
1803	collection = result.get();
1804
1805	// The operand needs to have object-pointer type.
1806	// TODO: should we do a contextual conversion?
1807	const ObjCObjectPointerType *pointerType =
1808	collection->getType()->getAs<ObjCObjectPointerType>();
1809	if (!pointerType)
1810	return Diag(forLoc, diag::err_collection_expr_type)
1811	<< collection->getType() << collection->getSourceRange();
1812
1813	// Check that the operand provides
1814	// - countByEnumeratingWithState:objects:count:
1815	const ObjCObjectType *objectType = pointerType->getObjectType();
1816	ObjCInterfaceDecl *iface = objectType->getInterface();
1817
1818	// If we have a forward-declared type, we can't do this check.
1819	// Under ARC, it is an error not to have a forward-declared class.
1820	if (iface &&
1821	(getLangOpts().ObjCAutoRefCount
1822	? RequireCompleteType(forLoc, QualType(objectType, 0),
1823	diag::err_arc_collection_forward, collection)
1824	: !isCompleteType(forLoc, QualType(objectType, 0)))) {
1825	// Otherwise, if we have any useful type information, check that
1826	// the type declares the appropriate method.
1827	} else if (iface \|\| !objectType->qual_empty()) {
1828	IdentifierInfo *selectorIdents[] = {
1829	&Context.Idents.get("countByEnumeratingWithState"),
1830	&Context.Idents.get("objects"),
1831	&Context.Idents.get("count")
1832	};
1833	Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]);
1834
1835	ObjCMethodDecl *method = nullptr;
1836
1837	// If there's an interface, look in both the public and private APIs.
1838	if (iface) {
1839	method = iface->lookupInstanceMethod(selector);
1840	if (!method) method = iface->lookupPrivateMethod(selector);
1841	}
1842
1843	// Also check protocol qualifiers.
1844	if (!method)
1845	method = LookupMethodInQualifiedType(selector, pointerType,
1846	/instance/ true);
1847
1848	// If we didn't find it anywhere, give up.
1849	if (!method) {
1850	Diag(forLoc, diag::warn_collection_expr_type)
1851	<< collection->getType() << selector << collection->getSourceRange();
1852	}
1853
1854	// TODO: check for an incompatible signature?
1855	}
1856
1857	// Wrap up any cleanups in the expression.
1858	return collection;
1859	}
1860
1861	StmtResult
1862	Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
1863	Stmt First, Expr collection,
1864	SourceLocation RParenLoc) {
1865	setFunctionHasBranchProtectedScope();
1866
1867	ExprResult CollectionExprResult =
1868	CheckObjCForCollectionOperand(ForLoc, collection);
1869
1870	if (First) {
1871	QualType FirstType;
1872	if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
1873	if (!DS->isSingleDecl())
1874	return StmtError(Diag((*DS->decl_begin())->getLocation(),
1875	diag::err_toomany_element_decls));
1876
1877	VarDecl *D = dyn_cast<VarDecl>(DS->getSingleDecl());
1878	if (!D \|\| D->isInvalidDecl())
1879	return StmtError();
1880
1881	FirstType = D->getType();
1882	// C99 6.8.5p3: The declaration part of a 'for' statement shall only
1883	// declare identifiers for objects having storage class 'auto' or
1884	// 'register'.
1885	if (!D->hasLocalStorage())
1886	return StmtError(Diag(D->getLocation(),
1887	diag::err_non_local_variable_decl_in_for));
1888
1889	// If the type contained 'auto', deduce the 'auto' to 'id'.
1890	if (FirstType->getContainedAutoType()) {
1891	OpaqueValueExpr OpaqueId(D->getLocation(), Context.getObjCIdType(),
1892	VK_RValue);
1893	Expr *DeducedInit = &OpaqueId;
1894	if (DeduceAutoType(D->getTypeSourceInfo(), DeducedInit, FirstType) ==
1895	DAR_Failed)
1896	DiagnoseAutoDeductionFailure(D, DeducedInit);
1897	if (FirstType.isNull()) {
1898	D->setInvalidDecl();
1899	return StmtError();
1900	}
1901
1902	D->setType(FirstType);
1903
1904	if (!inTemplateInstantiation()) {
1905	SourceLocation Loc =
1906	D->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
1907	Diag(Loc, diag::warn_auto_var_is_id)
1908	<< D->getDeclName();
1909	}
1910	}
1911
1912	} else {
1913	Expr *FirstE = cast<Expr>(First);
1914	if (!FirstE->isTypeDependent() && !FirstE->isLValue())
1915	return StmtError(
1916	Diag(First->getBeginLoc(), diag::err_selector_element_not_lvalue)
1917	<< First->getSourceRange());
1918
1919	FirstType = static_cast<Expr*>(First)->getType();
1920	if (FirstType.isConstQualified())
1921	Diag(ForLoc, diag::err_selector_element_const_type)
1922	<< FirstType << First->getSourceRange();
1923	}
1924	if (!FirstType->isDependentType() &&
1925	!FirstType->isObjCObjectPointerType() &&
1926	!FirstType->isBlockPointerType())
1927	return StmtError(Diag(ForLoc, diag::err_selector_element_type)
1928	<< FirstType << First->getSourceRange());
1929	}
1930
1931	if (CollectionExprResult.isInvalid())
1932	return StmtError();
1933
1934	CollectionExprResult =
1935	ActOnFinishFullExpr(CollectionExprResult.get(), /DiscardedValue/ false);
1936	if (CollectionExprResult.isInvalid())
1937	return StmtError();
1938
1939	return new (Context) ObjCForCollectionStmt(First, CollectionExprResult.get(),
1940	nullptr, ForLoc, RParenLoc);
1941	}
1942
1943	/// Finish building a variable declaration for a for-range statement.
1944	/// \return true if an error occurs.
1945	static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl Decl, Expr Init,
1946	SourceLocation Loc, int DiagID) {
1947	if (Decl->getType()->isUndeducedType()) {
1948	ExprResult Res = SemaRef.CorrectDelayedTyposInExpr(Init);
1949	if (!Res.isUsable()) {
1950	Decl->setInvalidDecl();
1951	return true;
1952	}
1953	Init = Res.get();
1954	}
1955
1956	// Deduce the type for the iterator variable now rather than leaving it to
1957	// AddInitializerToDecl, so we can produce a more suitable diagnostic.
1958	QualType InitType;
1959	if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) \|\|
1960	SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitType) ==
1961	Sema::DAR_Failed)
1962	SemaRef.Diag(Loc, DiagID) << Init->getType();
1963	if (InitType.isNull()) {
1964	Decl->setInvalidDecl();
1965	return true;
1966	}
1967	Decl->setType(InitType);
1968
1969	// In ARC, infer lifetime.
1970	// FIXME: ARC may want to turn this into 'const __unsafe_unretained' if
1971	// we're doing the equivalent of fast iteration.
1972	if (SemaRef.getLangOpts().ObjCAutoRefCount &&
1973	SemaRef.inferObjCARCLifetime(Decl))
1974	Decl->setInvalidDecl();
1975
1976	SemaRef.AddInitializerToDecl(Decl, Init, /DirectInit=/false);
1977	SemaRef.FinalizeDeclaration(Decl);
1978	SemaRef.CurContext->addHiddenDecl(Decl);
1979	return false;
1980	}
1981
1982	namespace {
1983	// An enum to represent whether something is dealing with a call to begin()
1984	// or a call to end() in a range-based for loop.
1985	enum BeginEndFunction {
1986	BEF_begin,
1987	BEF_end
1988	};
1989
1990	/// Produce a note indicating which begin/end function was implicitly called
1991	/// by a C++11 for-range statement. This is often not obvious from the code,
1992	/// nor from the diagnostics produced when analysing the implicit expressions
1993	/// required in a for-range statement.
1994	void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E,
1995	BeginEndFunction BEF) {
1996	CallExpr *CE = dyn_cast<CallExpr>(E);
1997	if (!CE)
1998	return;
1999	FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
2000	if (!D)
2001	return;
2002	SourceLocation Loc = D->getLocation();
2003
2004	std::string Description;
2005	bool IsTemplate = false;
2006	if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) {
2007	Description = SemaRef.getTemplateArgumentBindingsText(
2008	FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs());
2009	IsTemplate = true;
2010	}
2011
2012	SemaRef.Diag(Loc, diag::note_for_range_begin_end)
2013	<< BEF << IsTemplate << Description << E->getType();
2014	}
2015
2016	/// Build a variable declaration for a for-range statement.
2017	VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc,
2018	QualType Type, StringRef Name) {
2019	DeclContext *DC = SemaRef.CurContext;
2020	IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name);
2021	TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc);
2022	VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type,
2023	TInfo, SC_None);
2024	Decl->setImplicit();
2025	return Decl;
2026	}
2027
2028	}
2029
2030	static bool ObjCEnumerationCollection(Expr *Collection) {
2031	return !Collection->isTypeDependent()
2032	&& Collection->getType()->getAs<ObjCObjectPointerType>() != nullptr;
2033	}
2034
2035	/// ActOnCXXForRangeStmt - Check and build a C++11 for-range statement.
2036	///
2037	/// C++11 [stmt.ranged]:
2038	/// A range-based for statement is equivalent to
2039	///
2040	/// {
2041	/// auto && __range = range-init;
2042	/// for ( auto __begin = begin-expr,
2043	/// __end = end-expr;
2044	/// __begin != __end;
2045	/// ++__begin ) {
2046	/// for-range-declaration = *__begin;
2047	/// statement
2048	/// }
2049	/// }
2050	///
2051	/// The body of the loop is not available yet, since it cannot be analysed until
2052	/// we have determined the type of the for-range-declaration.
2053	StmtResult Sema::ActOnCXXForRangeStmt(Scope *S, SourceLocation ForLoc,
2054	SourceLocation CoawaitLoc, Stmt *InitStmt,
2055	Stmt *First, SourceLocation ColonLoc,
2056	Expr *Range, SourceLocation RParenLoc,
2057	BuildForRangeKind Kind) {
2058	if (!First)
2059	return StmtError();
2060
2061	if (Range && ObjCEnumerationCollection(Range)) {
2062	// FIXME: Support init-statements in Objective-C++20 ranged for statement.
2063	if (InitStmt)
2064	return Diag(InitStmt->getBeginLoc(), diag::err_objc_for_range_init_stmt)
2065	<< InitStmt->getSourceRange();
2066	return ActOnObjCForCollectionStmt(ForLoc, First, Range, RParenLoc);
2067	}
2068
2069	DeclStmt *DS = dyn_cast<DeclStmt>(First);
2070	(0) . __assert_fail ("DS && \"first part of for range not a decl stmt\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 2070, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(DS && "first part of for range not a decl stmt");
2071
2072	if (!DS->isSingleDecl()) {
2073	Diag(DS->getBeginLoc(), diag::err_type_defined_in_for_range);
2074	return StmtError();
2075	}
2076
2077	Decl *LoopVar = DS->getSingleDecl();
2078	if (LoopVar->isInvalidDecl() \|\| !Range \|\|
2079	DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) {
2080	LoopVar->setInvalidDecl();
2081	return StmtError();
2082	}
2083
2084	// Build the coroutine state immediately and not later during template
2085	// instantiation
2086	if (!CoawaitLoc.isInvalid()) {
2087	if (!ActOnCoroutineBodyStart(S, CoawaitLoc, "co_await"))
2088	return StmtError();
2089	}
2090
2091	// Build auto && __range = range-init
2092	// Divide by 2, since the variables are in the inner scope (loop body).
2093	const auto DepthStr = std::to_string(S->getDepth() / 2);
2094	SourceLocation RangeLoc = Range->getBeginLoc();
2095	VarDecl RangeVar = BuildForRangeVarDecl(this, RangeLoc,
2096	Context.getAutoRRefDeductType(),
2097	std::string("__range") + DepthStr);
2098	if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc,
2099	diag::err_for_range_deduction_failure)) {
2100	LoopVar->setInvalidDecl();
2101	return StmtError();
2102	}
2103
2104	// Claim the type doesn't contain auto: we've already done the checking.
2105	DeclGroupPtrTy RangeGroup =
2106	BuildDeclaratorGroup(MutableArrayRef<Decl >((Decl *)&RangeVar, 1));
2107	StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc);
2108	if (RangeDecl.isInvalid()) {
2109	LoopVar->setInvalidDecl();
2110	return StmtError();
2111	}
2112
2113	return BuildCXXForRangeStmt(
2114	ForLoc, CoawaitLoc, InitStmt, ColonLoc, RangeDecl.get(),
2115	/BeginStmt=/nullptr, /EndStmt=/nullptr,
2116	/Cond=/nullptr, /Inc=/nullptr, DS, RParenLoc, Kind);
2117	}
2118
2119	/// Create the initialization, compare, and increment steps for
2120	/// the range-based for loop expression.
2121	/// This function does not handle array-based for loops,
2122	/// which are created in Sema::BuildCXXForRangeStmt.
2123	///
2124	/// \returns a ForRangeStatus indicating success or what kind of error occurred.
2125	/// BeginExpr and EndExpr are set and FRS_Success is returned on success;
2126	/// CandidateSet and BEF are set and some non-success value is returned on
2127	/// failure.
2128	static Sema::ForRangeStatus
2129	BuildNonArrayForRange(Sema &SemaRef, Expr BeginRange, Expr EndRange,
2130	QualType RangeType, VarDecl BeginVar, VarDecl EndVar,
2131	SourceLocation ColonLoc, SourceLocation CoawaitLoc,
2132	OverloadCandidateSet CandidateSet, ExprResult BeginExpr,
2133	ExprResult EndExpr, BeginEndFunction BEF) {
2134	DeclarationNameInfo BeginNameInfo(
2135	&SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc);
2136	DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"),
2137	ColonLoc);
2138
2139	LookupResult BeginMemberLookup(SemaRef, BeginNameInfo,
2140	Sema::LookupMemberName);
2141	LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName);
2142
2143	auto BuildBegin = [&] {
2144	*BEF = BEF_begin;
2145	Sema::ForRangeStatus RangeStatus =
2146	SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, BeginNameInfo,
2147	BeginMemberLookup, CandidateSet,
2148	BeginRange, BeginExpr);
2149
2150	if (RangeStatus != Sema::FRS_Success) {
2151	if (RangeStatus == Sema::FRS_DiagnosticIssued)
2152	SemaRef.Diag(BeginRange->getBeginLoc(), diag::note_in_for_range)
2153	<< ColonLoc << BEF_begin << BeginRange->getType();
2154	return RangeStatus;
2155	}
2156	if (!CoawaitLoc.isInvalid()) {
2157	// FIXME: getCurScope() should not be used during template instantiation.
2158	// We should pick up the set of unqualified lookup results for operator
2159	// co_await during the initial parse.
2160	*BeginExpr = SemaRef.ActOnCoawaitExpr(SemaRef.getCurScope(), ColonLoc,
2161	BeginExpr->get());
2162	if (BeginExpr->isInvalid())
2163	return Sema::FRS_DiagnosticIssued;
2164	}
2165	if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc,
2166	diag::err_for_range_iter_deduction_failure)) {
2167	NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF);
2168	return Sema::FRS_DiagnosticIssued;
2169	}
2170	return Sema::FRS_Success;
2171	};
2172
2173	auto BuildEnd = [&] {
2174	*BEF = BEF_end;
2175	Sema::ForRangeStatus RangeStatus =
2176	SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, EndNameInfo,
2177	EndMemberLookup, CandidateSet,
2178	EndRange, EndExpr);
2179	if (RangeStatus != Sema::FRS_Success) {
2180	if (RangeStatus == Sema::FRS_DiagnosticIssued)
2181	SemaRef.Diag(EndRange->getBeginLoc(), diag::note_in_for_range)
2182	<< ColonLoc << BEF_end << EndRange->getType();
2183	return RangeStatus;
2184	}
2185	if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc,
2186	diag::err_for_range_iter_deduction_failure)) {
2187	NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF);
2188	return Sema::FRS_DiagnosticIssued;
2189	}
2190	return Sema::FRS_Success;
2191	};
2192
2193	if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) {
2194	// - if _RangeT is a class type, the unqualified-ids begin and end are
2195	// looked up in the scope of class _RangeT as if by class member access
2196	// lookup (3.4.5), and if either (or both) finds at least one
2197	// declaration, begin-expr and end-expr are __range.begin() and
2198	// __range.end(), respectively;
2199	SemaRef.LookupQualifiedName(BeginMemberLookup, D);
2200	if (BeginMemberLookup.isAmbiguous())
2201	return Sema::FRS_DiagnosticIssued;
2202
2203	SemaRef.LookupQualifiedName(EndMemberLookup, D);
2204	if (EndMemberLookup.isAmbiguous())
2205	return Sema::FRS_DiagnosticIssued;
2206
2207	if (BeginMemberLookup.empty() != EndMemberLookup.empty()) {
2208	// Look up the non-member form of the member we didn't find, first.
2209	// This way we prefer a "no viable 'end'" diagnostic over a "i found
2210	// a 'begin' but ignored it because there was no member 'end'"
2211	// diagnostic.
2212	auto BuildNonmember = [&](
2213	BeginEndFunction BEFFound, LookupResult &Found,
2214	llvm::function_ref<Sema::ForRangeStatus()> BuildFound,
2215	llvm::function_ref<Sema::ForRangeStatus()> BuildNotFound) {
2216	LookupResult OldFound = std::move(Found);
2217	Found.clear();
2218
2219	if (Sema::ForRangeStatus Result = BuildNotFound())
2220	return Result;
2221
2222	switch (BuildFound()) {
2223	case Sema::FRS_Success:
2224	return Sema::FRS_Success;
2225
2226	case Sema::FRS_NoViableFunction:
2227	SemaRef.Diag(BeginRange->getBeginLoc(), diag::err_for_range_invalid)
2228	<< BeginRange->getType() << BEFFound;
2229	CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, BeginRange);
2230	LLVM_FALLTHROUGH;
2231
2232	case Sema::FRS_DiagnosticIssued:
2233	for (NamedDecl *D : OldFound) {
2234	SemaRef.Diag(D->getLocation(),
2235	diag::note_for_range_member_begin_end_ignored)
2236	<< BeginRange->getType() << BEFFound;
2237	}
2238	return Sema::FRS_DiagnosticIssued;
2239	}
2240	llvm_unreachable("unexpected ForRangeStatus");
2241	};
2242	if (BeginMemberLookup.empty())
2243	return BuildNonmember(BEF_end, EndMemberLookup, BuildEnd, BuildBegin);
2244	return BuildNonmember(BEF_begin, BeginMemberLookup, BuildBegin, BuildEnd);
2245	}
2246	} else {
2247	// - otherwise, begin-expr and end-expr are begin(__range) and
2248	// end(__range), respectively, where begin and end are looked up with
2249	// argument-dependent lookup (3.4.2). For the purposes of this name
2250	// lookup, namespace std is an associated namespace.
2251	}
2252
2253	if (Sema::ForRangeStatus Result = BuildBegin())
2254	return Result;
2255	return BuildEnd();
2256	}
2257
2258	/// Speculatively attempt to dereference an invalid range expression.
2259	/// If the attempt fails, this function will return a valid, null StmtResult
2260	/// and emit no diagnostics.
2261	static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S,
2262	SourceLocation ForLoc,
2263	SourceLocation CoawaitLoc,
2264	Stmt *InitStmt,
2265	Stmt *LoopVarDecl,
2266	SourceLocation ColonLoc,
2267	Expr *Range,
2268	SourceLocation RangeLoc,
2269	SourceLocation RParenLoc) {
2270	// Determine whether we can rebuild the for-range statement with a
2271	// dereferenced range expression.
2272	ExprResult AdjustedRange;
2273	{
2274	Sema::SFINAETrap Trap(SemaRef);
2275
2276	AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range);
2277	if (AdjustedRange.isInvalid())
2278	return StmtResult();
2279
2280	StmtResult SR = SemaRef.ActOnCXXForRangeStmt(
2281	S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc,
2282	AdjustedRange.get(), RParenLoc, Sema::BFRK_Check);
2283	if (SR.isInvalid())
2284	return StmtResult();
2285	}
2286
2287	// The attempt to dereference worked well enough that it could produce a valid
2288	// loop. Produce a fixit, and rebuild the loop with diagnostics enabled, in
2289	// case there are any other (non-fatal) problems with it.
2290	SemaRef.Diag(RangeLoc, diag::err_for_range_dereference)
2291	<< Range->getType() << FixItHint::CreateInsertion(RangeLoc, "*");
2292	return SemaRef.ActOnCXXForRangeStmt(
2293	S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc,
2294	AdjustedRange.get(), RParenLoc, Sema::BFRK_Rebuild);
2295	}
2296
2297	namespace {
2298	/// RAII object to automatically invalidate a declaration if an error occurs.
2299	struct InvalidateOnErrorScope {
2300	InvalidateOnErrorScope(Sema &SemaRef, Decl *D, bool Enabled)
2301	: Trap(SemaRef.Diags), D(D), Enabled(Enabled) {}
2302	~InvalidateOnErrorScope() {
2303	if (Enabled && Trap.hasErrorOccurred())
2304	D->setInvalidDecl();
2305	}
2306
2307	DiagnosticErrorTrap Trap;
2308	Decl *D;
2309	bool Enabled;
2310	};
2311	}
2312
2313	/// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement.
2314	StmtResult Sema::BuildCXXForRangeStmt(SourceLocation ForLoc,
2315	SourceLocation CoawaitLoc, Stmt *InitStmt,
2316	SourceLocation ColonLoc, Stmt *RangeDecl,
2317	Stmt Begin, Stmt End, Expr *Cond,
2318	Expr Inc, Stmt LoopVarDecl,
2319	SourceLocation RParenLoc,
2320	BuildForRangeKind Kind) {
2321	// FIXME: This should not be used during template instantiation. We should
2322	// pick up the set of unqualified lookup results for the != and + operators
2323	// in the initial parse.
2324	//
2325	// Testcase (accepts-invalid):
2326	// template<typename T> void f() { for (auto x : T()) {} }
2327	// namespace N { struct X { X begin(); X end(); int operator*(); }; }
2328	// bool operator!=(N::X, N::X); void operator++(N::X);
2329	// void g() { f<N::X>(); }
2330	Scope *S = getCurScope();
2331
2332	DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl);
2333	VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl());
2334	QualType RangeVarType = RangeVar->getType();
2335
2336	DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl);
2337	VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl());
2338
2339	// If we hit any errors, mark the loop variable as invalid if its type
2340	// contains 'auto'.
2341	InvalidateOnErrorScope Invalidate(*this, LoopVar,
2342	LoopVar->getType()->isUndeducedType());
2343
2344	StmtResult BeginDeclStmt = Begin;
2345	StmtResult EndDeclStmt = End;
2346	ExprResult NotEqExpr = Cond, IncrExpr = Inc;
2347
2348	if (RangeVarType->isDependentType()) {
2349	// The range is implicitly used as a placeholder when it is dependent.
2350	RangeVar->markUsed(Context);
2351
2352	// Deduce any 'auto's in the loop variable as 'DependentTy'. We'll fill
2353	// them in properly when we instantiate the loop.
2354	if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) {
2355	if (auto *DD = dyn_cast<DecompositionDecl>(LoopVar))
2356	for (auto *Binding : DD->bindings())
2357	Binding->setType(Context.DependentTy);
2358	LoopVar->setType(SubstAutoType(LoopVar->getType(), Context.DependentTy));
2359	}
2360	} else if (!BeginDeclStmt.get()) {
2361	SourceLocation RangeLoc = RangeVar->getLocation();
2362
2363	const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType();
2364
2365	ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
2366	VK_LValue, ColonLoc);
2367	if (BeginRangeRef.isInvalid())
2368	return StmtError();
2369
2370	ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
2371	VK_LValue, ColonLoc);
2372	if (EndRangeRef.isInvalid())
2373	return StmtError();
2374
2375	QualType AutoType = Context.getAutoDeductType();
2376	Expr *Range = RangeVar->getInit();
2377	if (!Range)
2378	return StmtError();
2379	QualType RangeType = Range->getType();
2380
2381	if (RequireCompleteType(RangeLoc, RangeType,
2382	diag::err_for_range_incomplete_type))
2383	return StmtError();
2384
2385	// Build auto __begin = begin-expr, __end = end-expr.
2386	// Divide by 2, since the variables are in the inner scope (loop body).
2387	const auto DepthStr = std::to_string(S->getDepth() / 2);
2388	VarDecl BeginVar = BuildForRangeVarDecl(this, ColonLoc, AutoType,
2389	std::string("__begin") + DepthStr);
2390	VarDecl EndVar = BuildForRangeVarDecl(this, ColonLoc, AutoType,
2391	std::string("__end") + DepthStr);
2392
2393	// Build begin-expr and end-expr and attach to __begin and __end variables.
2394	ExprResult BeginExpr, EndExpr;
2395	if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) {
2396	// - if _RangeT is an array type, begin-expr and end-expr are __range and
2397	// __range + __bound, respectively, where __bound is the array bound. If
2398	// _RangeT is an array of unknown size or an array of incomplete type,
2399	// the program is ill-formed;
2400
2401	// begin-expr is __range.
2402	BeginExpr = BeginRangeRef;
2403	if (!CoawaitLoc.isInvalid()) {
2404	BeginExpr = ActOnCoawaitExpr(S, ColonLoc, BeginExpr.get());
2405	if (BeginExpr.isInvalid())
2406	return StmtError();
2407	}
2408	if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc,
2409	diag::err_for_range_iter_deduction_failure)) {
2410	NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2411	return StmtError();
2412	}
2413
2414	// Find the array bound.
2415	ExprResult BoundExpr;
2416	if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT))
2417	BoundExpr = IntegerLiteral::Create(
2418	Context, CAT->getSize(), Context.getPointerDiffType(), RangeLoc);
2419	else if (const VariableArrayType *VAT =
2420	dyn_cast<VariableArrayType>(UnqAT)) {
2421	// For a variably modified type we can't just use the expression within
2422	// the array bounds, since we don't want that to be re-evaluated here.
2423	// Rather, we need to determine what it was when the array was first
2424	// created - so we resort to using sizeof(vla)/sizeof(element).
2425	// For e.g.
2426	// void f(int b) {
2427	// int vla[b];
2428	// b = -1; <-- This should not affect the num of iterations below
2429	// for (int &c : vla) { .. }
2430	// }
2431
2432	// FIXME: This results in codegen generating IR that recalculates the
2433	// run-time number of elements (as opposed to just using the IR Value
2434	// that corresponds to the run-time value of each bound that was
2435	// generated when the array was created.) If this proves too embarrassing
2436	// even for unoptimized IR, consider passing a magic-value/cookie to
2437	// codegen that then knows to simply use that initial llvm::Value (that
2438	// corresponds to the bound at time of array creation) within
2439	// getelementptr. But be prepared to pay the price of increasing a
2440	// customized form of coupling between the two components - which could
2441	// be hard to maintain as the codebase evolves.
2442
2443	ExprResult SizeOfVLAExprR = ActOnUnaryExprOrTypeTraitExpr(
2444	EndVar->getLocation(), UETT_SizeOf,
2445	/isType=/true,
2446	CreateParsedType(VAT->desugar(), Context.getTrivialTypeSourceInfo(
2447	VAT->desugar(), RangeLoc))
2448	.getAsOpaquePtr(),
2449	EndVar->getSourceRange());
2450	if (SizeOfVLAExprR.isInvalid())
2451	return StmtError();
2452
2453	ExprResult SizeOfEachElementExprR = ActOnUnaryExprOrTypeTraitExpr(
2454	EndVar->getLocation(), UETT_SizeOf,
2455	/isType=/true,
2456	CreateParsedType(VAT->desugar(),
2457	Context.getTrivialTypeSourceInfo(
2458	VAT->getElementType(), RangeLoc))
2459	.getAsOpaquePtr(),
2460	EndVar->getSourceRange());
2461	if (SizeOfEachElementExprR.isInvalid())
2462	return StmtError();
2463
2464	BoundExpr =
2465	ActOnBinOp(S, EndVar->getLocation(), tok::slash,
2466	SizeOfVLAExprR.get(), SizeOfEachElementExprR.get());
2467	if (BoundExpr.isInvalid())
2468	return StmtError();
2469
2470	} else {
2471	// Can't be a DependentSizedArrayType or an IncompleteArrayType since
2472	// UnqAT is not incomplete and Range is not type-dependent.
2473	llvm_unreachable("Unexpected array type in for-range");
2474	}
2475
2476	// end-expr is __range + __bound.
2477	EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(),
2478	BoundExpr.get());
2479	if (EndExpr.isInvalid())
2480	return StmtError();
2481	if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc,
2482	diag::err_for_range_iter_deduction_failure)) {
2483	NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2484	return StmtError();
2485	}
2486	} else {
2487	OverloadCandidateSet CandidateSet(RangeLoc,
2488	OverloadCandidateSet::CSK_Normal);
2489	BeginEndFunction BEFFailure;
2490	ForRangeStatus RangeStatus = BuildNonArrayForRange(
2491	*this, BeginRangeRef.get(), EndRangeRef.get(), RangeType, BeginVar,
2492	EndVar, ColonLoc, CoawaitLoc, &CandidateSet, &BeginExpr, &EndExpr,
2493	&BEFFailure);
2494
2495	if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction &&
2496	BEFFailure == BEF_begin) {
2497	// If the range is being built from an array parameter, emit a
2498	// a diagnostic that it is being treated as a pointer.
2499	if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Range)) {
2500	if (ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
2501	QualType ArrayTy = PVD->getOriginalType();
2502	QualType PointerTy = PVD->getType();
2503	if (PointerTy->isPointerType() && ArrayTy->isArrayType()) {
2504	Diag(Range->getBeginLoc(), diag::err_range_on_array_parameter)
2505	<< RangeLoc << PVD << ArrayTy << PointerTy;
2506	Diag(PVD->getLocation(), diag::note_declared_at);
2507	return StmtError();
2508	}
2509	}
2510	}
2511
2512	// If building the range failed, try dereferencing the range expression
2513	// unless a diagnostic was issued or the end function is problematic.
2514	StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc,
2515	CoawaitLoc, InitStmt,
2516	LoopVarDecl, ColonLoc,
2517	Range, RangeLoc,
2518	RParenLoc);
2519	if (SR.isInvalid() \|\| SR.isUsable())
2520	return SR;
2521	}
2522
2523	// Otherwise, emit diagnostics if we haven't already.
2524	if (RangeStatus == FRS_NoViableFunction) {
2525	Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get();
2526	Diag(Range->getBeginLoc(), diag::err_for_range_invalid)
2527	<< RangeLoc << Range->getType() << BEFFailure;
2528	CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Range);
2529	}
2530	// Return an error if no fix was discovered.
2531	if (RangeStatus != FRS_Success)
2532	return StmtError();
2533	}
2534
2535	(0) . __assert_fail ("!BeginExpr.isInvalid() && !EndExpr.isInvalid() && \"invalid range expression in for loop\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 2536, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() &&
2536	(0) . __assert_fail ("!BeginExpr.isInvalid() && !EndExpr.isInvalid() && \"invalid range expression in for loop\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 2536, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "invalid range expression in for loop");
2537
2538	// C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same.
2539	// C++1z removes this restriction.
2540	QualType BeginType = BeginVar->getType(), EndType = EndVar->getType();
2541	if (!Context.hasSameType(BeginType, EndType)) {
2542	Diag(RangeLoc, getLangOpts().CPlusPlus17
2543	? diag::warn_for_range_begin_end_types_differ
2544	: diag::ext_for_range_begin_end_types_differ)
2545	<< BeginType << EndType;
2546	NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2547	NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2548	}
2549
2550	BeginDeclStmt =
2551	ActOnDeclStmt(ConvertDeclToDeclGroup(BeginVar), ColonLoc, ColonLoc);
2552	EndDeclStmt =
2553	ActOnDeclStmt(ConvertDeclToDeclGroup(EndVar), ColonLoc, ColonLoc);
2554
2555	const QualType BeginRefNonRefType = BeginType.getNonReferenceType();
2556	ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2557	VK_LValue, ColonLoc);
2558	if (BeginRef.isInvalid())
2559	return StmtError();
2560
2561	ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(),
2562	VK_LValue, ColonLoc);
2563	if (EndRef.isInvalid())
2564	return StmtError();
2565
2566	// Build and check __begin != __end expression.
2567	NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal,
2568	BeginRef.get(), EndRef.get());
2569	if (!NotEqExpr.isInvalid())
2570	NotEqExpr = CheckBooleanCondition(ColonLoc, NotEqExpr.get());
2571	if (!NotEqExpr.isInvalid())
2572	NotEqExpr =
2573	ActOnFinishFullExpr(NotEqExpr.get(), /DiscardedValue/ false);
2574	if (NotEqExpr.isInvalid()) {
2575	Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2576	<< RangeLoc << 0 << BeginRangeRef.get()->getType();
2577	NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2578	if (!Context.hasSameType(BeginType, EndType))
2579	NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2580	return StmtError();
2581	}
2582
2583	// Build and check ++__begin expression.
2584	BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2585	VK_LValue, ColonLoc);
2586	if (BeginRef.isInvalid())
2587	return StmtError();
2588
2589	IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get());
2590	if (!IncrExpr.isInvalid() && CoawaitLoc.isValid())
2591	// FIXME: getCurScope() should not be used during template instantiation.
2592	// We should pick up the set of unqualified lookup results for operator
2593	// co_await during the initial parse.
2594	IncrExpr = ActOnCoawaitExpr(S, CoawaitLoc, IncrExpr.get());
2595	if (!IncrExpr.isInvalid())
2596	IncrExpr = ActOnFinishFullExpr(IncrExpr.get(), /DiscardedValue/ false);
2597	if (IncrExpr.isInvalid()) {
2598	Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2599	<< RangeLoc << 2 << BeginRangeRef.get()->getType() ;
2600	NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2601	return StmtError();
2602	}
2603
2604	// Build and check *__begin expression.
2605	BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2606	VK_LValue, ColonLoc);
2607	if (BeginRef.isInvalid())
2608	return StmtError();
2609
2610	ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get());
2611	if (DerefExpr.isInvalid()) {
2612	Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2613	<< RangeLoc << 1 << BeginRangeRef.get()->getType();
2614	NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2615	return StmtError();
2616	}
2617
2618	// Attach *__begin as initializer for VD. Don't touch it if we're just
2619	// trying to determine whether this would be a valid range.
2620	if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) {
2621	AddInitializerToDecl(LoopVar, DerefExpr.get(), /DirectInit=/false);
2622	if (LoopVar->isInvalidDecl())
2623	NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2624	}
2625	}
2626
2627	// Don't bother to actually allocate the result if we're just trying to
2628	// determine whether it would be valid.
2629	if (Kind == BFRK_Check)
2630	return StmtResult();
2631
2632	return new (Context) CXXForRangeStmt(
2633	InitStmt, RangeDS, cast_or_null<DeclStmt>(BeginDeclStmt.get()),
2634	cast_or_null<DeclStmt>(EndDeclStmt.get()), NotEqExpr.get(),
2635	IncrExpr.get(), LoopVarDS, /Body=/nullptr, ForLoc, CoawaitLoc,
2636	ColonLoc, RParenLoc);
2637	}
2638
2639	/// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach
2640	/// statement.
2641	StmtResult Sema::FinishObjCForCollectionStmt(Stmt S, Stmt B) {
2642	if (!S \|\| !B)
2643	return StmtError();
2644	ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S);
2645
2646	ForStmt->setBody(B);
2647	return S;
2648	}
2649
2650	// Warn when the loop variable is a const reference that creates a copy.
2651	// Suggest using the non-reference type for copies. If a copy can be prevented
2652	// suggest the const reference type that would do so.
2653	// For instance, given "for (const &Foo : Range)", suggest
2654	// "for (const Foo : Range)" to denote a copy is made for the loop. If
2655	// possible, also suggest "for (const &Bar : Range)" if this type prevents
2656	// the copy altogether.
2657	static void DiagnoseForRangeReferenceVariableCopies(Sema &SemaRef,
2658	const VarDecl *VD,
2659	QualType RangeInitType) {
2660	const Expr *InitExpr = VD->getInit();
2661	if (!InitExpr)
2662	return;
2663
2664	QualType VariableType = VD->getType();
2665
2666	if (auto Cleanups = dyn_cast<ExprWithCleanups>(InitExpr))
2667	if (!Cleanups->cleanupsHaveSideEffects())
2668	InitExpr = Cleanups->getSubExpr();
2669
2670	const MaterializeTemporaryExpr *MTE =
2671	dyn_cast<MaterializeTemporaryExpr>(InitExpr);
2672
2673	// No copy made.
2674	if (!MTE)
2675	return;
2676
2677	const Expr *E = MTE->GetTemporaryExpr()->IgnoreImpCasts();
2678
2679	// Searching for either UnaryOperator for dereference of a pointer or
2680	// CXXOperatorCallExpr for handling iterators.
2681	while (!isa<CXXOperatorCallExpr>(E) && !isa<UnaryOperator>(E)) {
2682	if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(E)) {
2683	E = CCE->getArg(0);
2684	} else if (const CXXMemberCallExpr *Call = dyn_cast<CXXMemberCallExpr>(E)) {
2685	const MemberExpr *ME = cast<MemberExpr>(Call->getCallee());
2686	E = ME->getBase();
2687	} else {
2688	const MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(E);
2689	E = MTE->GetTemporaryExpr();
2690	}
2691	E = E->IgnoreImpCasts();
2692	}
2693
2694	bool ReturnsReference = false;
2695	if (isa<UnaryOperator>(E)) {
2696	ReturnsReference = true;
2697	} else {
2698	const CXXOperatorCallExpr *Call = cast<CXXOperatorCallExpr>(E);
2699	const FunctionDecl *FD = Call->getDirectCallee();
2700	QualType ReturnType = FD->getReturnType();
2701	ReturnsReference = ReturnType->isReferenceType();
2702	}
2703
2704	if (ReturnsReference) {
2705	// Loop variable creates a temporary. Suggest either to go with
2706	// non-reference loop variable to indicate a copy is made, or
2707	// the correct time to bind a const reference.
2708	SemaRef.Diag(VD->getLocation(), diag::warn_for_range_const_reference_copy)
2709	<< VD << VariableType << E->getType();
2710	QualType NonReferenceType = VariableType.getNonReferenceType();
2711	NonReferenceType.removeLocalConst();
2712	QualType NewReferenceType =
2713	SemaRef.Context.getLValueReferenceType(E->getType().withConst());
2714	SemaRef.Diag(VD->getBeginLoc(), diag::note_use_type_or_non_reference)
2715	<< NonReferenceType << NewReferenceType << VD->getSourceRange();
2716	} else {
2717	// The range always returns a copy, so a temporary is always created.
2718	// Suggest removing the reference from the loop variable.
2719	SemaRef.Diag(VD->getLocation(), diag::warn_for_range_variable_always_copy)
2720	<< VD << RangeInitType;
2721	QualType NonReferenceType = VariableType.getNonReferenceType();
2722	NonReferenceType.removeLocalConst();
2723	SemaRef.Diag(VD->getBeginLoc(), diag::note_use_non_reference_type)
2724	<< NonReferenceType << VD->getSourceRange();
2725	}
2726	}
2727
2728	// Warns when the loop variable can be changed to a reference type to
2729	// prevent a copy. For instance, if given "for (const Foo x : Range)" suggest
2730	// "for (const Foo &x : Range)" if this form does not make a copy.
2731	static void DiagnoseForRangeConstVariableCopies(Sema &SemaRef,
2732	const VarDecl *VD) {
2733	const Expr *InitExpr = VD->getInit();
2734	if (!InitExpr)
2735	return;
2736
2737	QualType VariableType = VD->getType();
2738
2739	if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(InitExpr)) {
2740	if (!CE->getConstructor()->isCopyConstructor())
2741	return;
2742	} else if (const CastExpr *CE = dyn_cast<CastExpr>(InitExpr)) {
2743	if (CE->getCastKind() != CK_LValueToRValue)
2744	return;
2745	} else {
2746	return;
2747	}
2748
2749	// TODO: Determine a maximum size that a POD type can be before a diagnostic
2750	// should be emitted. Also, only ignore POD types with trivial copy
2751	// constructors.
2752	if (VariableType.isPODType(SemaRef.Context))
2753	return;
2754
2755	// Suggest changing from a const variable to a const reference variable
2756	// if doing so will prevent a copy.
2757	SemaRef.Diag(VD->getLocation(), diag::warn_for_range_copy)
2758	<< VD << VariableType << InitExpr->getType();
2759	SemaRef.Diag(VD->getBeginLoc(), diag::note_use_reference_type)
2760	<< SemaRef.Context.getLValueReferenceType(VariableType)
2761	<< VD->getSourceRange();
2762	}
2763
2764	/// DiagnoseForRangeVariableCopies - Diagnose three cases and fixes for them.
2765	/// 1) for (const foo &x : foos) where foos only returns a copy. Suggest
2766	/// using "const foo x" to show that a copy is made
2767	/// 2) for (const bar &x : foos) where bar is a temporary initialized by bar.
2768	/// Suggest either "const bar x" to keep the copying or "const foo& x" to
2769	/// prevent the copy.
2770	/// 3) for (const foo x : foos) where x is constructed from a reference foo.
2771	/// Suggest "const foo &x" to prevent the copy.
2772	static void DiagnoseForRangeVariableCopies(Sema &SemaRef,
2773	const CXXForRangeStmt *ForStmt) {
2774	if (SemaRef.Diags.isIgnored(diag::warn_for_range_const_reference_copy,
2775	ForStmt->getBeginLoc()) &&
2776	SemaRef.Diags.isIgnored(diag::warn_for_range_variable_always_copy,
2777	ForStmt->getBeginLoc()) &&
2778	SemaRef.Diags.isIgnored(diag::warn_for_range_copy,
2779	ForStmt->getBeginLoc())) {
2780	return;
2781	}
2782
2783	const VarDecl *VD = ForStmt->getLoopVariable();
2784	if (!VD)
2785	return;
2786
2787	QualType VariableType = VD->getType();
2788
2789	if (VariableType->isIncompleteType())
2790	return;
2791
2792	const Expr *InitExpr = VD->getInit();
2793	if (!InitExpr)
2794	return;
2795
2796	if (VariableType->isReferenceType()) {
2797	DiagnoseForRangeReferenceVariableCopies(SemaRef, VD,
2798	ForStmt->getRangeInit()->getType());
2799	} else if (VariableType.isConstQualified()) {
2800	DiagnoseForRangeConstVariableCopies(SemaRef, VD);
2801	}
2802	}
2803
2804	/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement.
2805	/// This is a separate step from ActOnCXXForRangeStmt because analysis of the
2806	/// body cannot be performed until after the type of the range variable is
2807	/// determined.
2808	StmtResult Sema::FinishCXXForRangeStmt(Stmt S, Stmt B) {
2809	if (!S \|\| !B)
2810	return StmtError();
2811
2812	if (isa<ObjCForCollectionStmt>(S))
2813	return FinishObjCForCollectionStmt(S, B);
2814
2815	CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S);
2816	ForStmt->setBody(B);
2817
2818	DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B,
2819	diag::warn_empty_range_based_for_body);
2820
2821	DiagnoseForRangeVariableCopies(*this, ForStmt);
2822
2823	return S;
2824	}
2825
2826	StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc,
2827	SourceLocation LabelLoc,
2828	LabelDecl *TheDecl) {
2829	setFunctionHasBranchIntoScope();
2830	TheDecl->markUsed(Context);
2831	return new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc);
2832	}
2833
2834	StmtResult
2835	Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
2836	Expr *E) {
2837	// Convert operand to void*
2838	if (!E->isTypeDependent()) {
2839	QualType ETy = E->getType();
2840	QualType DestTy = Context.getPointerType(Context.VoidTy.withConst());
2841	ExprResult ExprRes = E;
2842	AssignConvertType ConvTy =
2843	CheckSingleAssignmentConstraints(DestTy, ExprRes);
2844	if (ExprRes.isInvalid())
2845	return StmtError();
2846	E = ExprRes.get();
2847	if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing))
2848	return StmtError();
2849	}
2850
2851	ExprResult ExprRes = ActOnFinishFullExpr(E, /DiscardedValue/ false);
2852	if (ExprRes.isInvalid())
2853	return StmtError();
2854	E = ExprRes.get();
2855
2856	setFunctionHasIndirectGoto();
2857
2858	return new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E);
2859	}
2860
2861	static void CheckJumpOutOfSEHFinally(Sema &S, SourceLocation Loc,
2862	const Scope &DestScope) {
2863	if (!S.CurrentSEHFinally.empty() &&
2864	DestScope.Contains(*S.CurrentSEHFinally.back())) {
2865	S.Diag(Loc, diag::warn_jump_out_of_seh_finally);
2866	}
2867	}
2868
2869	StmtResult
2870	Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
2871	Scope *S = CurScope->getContinueParent();
2872	if (!S) {
2873	// C99 6.8.6.2p1: A break shall appear only in or as a loop body.
2874	return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
2875	}
2876	CheckJumpOutOfSEHFinally(this, ContinueLoc, S);
2877
2878	return new (Context) ContinueStmt(ContinueLoc);
2879	}
2880
2881	StmtResult
2882	Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
2883	Scope *S = CurScope->getBreakParent();
2884	if (!S) {
2885	// C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
2886	return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
2887	}
2888	if (S->isOpenMPLoopScope())
2889	return StmtError(Diag(BreakLoc, diag::err_omp_loop_cannot_use_stmt)
2890	<< "break");
2891	CheckJumpOutOfSEHFinally(this, BreakLoc, S);
2892
2893	return new (Context) BreakStmt(BreakLoc);
2894	}
2895
2896	/// Determine whether the given expression is a candidate for
2897	/// copy elision in either a return statement or a throw expression.
2898	///
2899	/// \param ReturnType If we're determining the copy elision candidate for
2900	/// a return statement, this is the return type of the function. If we're
2901	/// determining the copy elision candidate for a throw expression, this will
2902	/// be a NULL type.
2903	///
2904	/// \param E The expression being returned from the function or block, or
2905	/// being thrown.
2906	///
2907	/// \param CESK Whether we allow function parameters or
2908	/// id-expressions that could be moved out of the function to be considered NRVO
2909	/// candidates. C++ prohibits these for NRVO itself, but we re-use this logic to
2910	/// determine whether we should try to move as part of a return or throw (which
2911	/// does allow function parameters).
2912	///
2913	/// \returns The NRVO candidate variable, if the return statement may use the
2914	/// NRVO, or NULL if there is no such candidate.
2915	VarDecl Sema::getCopyElisionCandidate(QualType ReturnType, Expr E,
2916	CopyElisionSemanticsKind CESK) {
2917	// - in a return statement in a function [where] ...
2918	// ... the expression is the name of a non-volatile automatic object ...
2919	DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
2920	if (!DR \|\| DR->refersToEnclosingVariableOrCapture())
2921	return nullptr;
2922	VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
2923	if (!VD)
2924	return nullptr;
2925
2926	if (isCopyElisionCandidate(ReturnType, VD, CESK))
2927	return VD;
2928	return nullptr;
2929	}
2930
2931	bool Sema::isCopyElisionCandidate(QualType ReturnType, const VarDecl *VD,
2932	CopyElisionSemanticsKind CESK) {
2933	QualType VDType = VD->getType();
2934	// - in a return statement in a function with ...
2935	// ... a class return type ...
2936	if (!ReturnType.isNull() && !ReturnType->isDependentType()) {
2937	if (!ReturnType->isRecordType())
2938	return false;
2939	// ... the same cv-unqualified type as the function return type ...
2940	// When considering moving this expression out, allow dissimilar types.
2941	if (!(CESK & CES_AllowDifferentTypes) && !VDType->isDependentType() &&
2942	!Context.hasSameUnqualifiedType(ReturnType, VDType))
2943	return false;
2944	}
2945
2946	// ...object (other than a function or catch-clause parameter)...
2947	if (VD->getKind() != Decl::Var &&
2948	!((CESK & CES_AllowParameters) && VD->getKind() == Decl::ParmVar))
2949	return false;
2950	if (!(CESK & CES_AllowExceptionVariables) && VD->isExceptionVariable())
2951	return false;
2952
2953	// ...automatic...
2954	if (!VD->hasLocalStorage()) return false;
2955
2956	// Return false if VD is a __block variable. We don't want to implicitly move
2957	// out of a __block variable during a return because we cannot assume the
2958	// variable will no longer be used.
2959	if (VD->hasAttr<BlocksAttr>()) return false;
2960
2961	if (CESK & CES_AllowDifferentTypes)
2962	return true;
2963
2964	// ...non-volatile...
2965	if (VD->getType().isVolatileQualified()) return false;
2966
2967	// Variables with higher required alignment than their type's ABI
2968	// alignment cannot use NRVO.
2969	if (!VD->getType()->isDependentType() && VD->hasAttr<AlignedAttr>() &&
2970	Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType()))
2971	return false;
2972
2973	return true;
2974	}
2975
2976	/// Try to perform the initialization of a potentially-movable value,
2977	/// which is the operand to a return or throw statement.
2978	///
2979	/// This routine implements C++14 [class.copy]p32, which attempts to treat
2980	/// returned lvalues as rvalues in certain cases (to prefer move construction),
2981	/// then falls back to treating them as lvalues if that failed.
2982	///
2983	/// \param ConvertingConstructorsOnly If true, follow [class.copy]p32 and reject
2984	/// resolutions that find non-constructors, such as derived-to-base conversions
2985	/// or `operator T()&&` member functions. If false, do consider such
2986	/// conversion sequences.
2987	///
2988	/// \param Res We will fill this in if move-initialization was possible.
2989	/// If move-initialization is not possible, such that we must fall back to
2990	/// treating the operand as an lvalue, we will leave Res in its original
2991	/// invalid state.
2992	static void TryMoveInitialization(Sema& S,
2993	const InitializedEntity &Entity,
2994	const VarDecl *NRVOCandidate,
2995	QualType ResultType,
2996	Expr *&Value,
2997	bool ConvertingConstructorsOnly,
2998	ExprResult &Res) {
2999	ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, Value->getType(),
3000	CK_NoOp, Value, VK_XValue);
3001
3002	Expr *InitExpr = &AsRvalue;
3003
3004	InitializationKind Kind = InitializationKind::CreateCopy(
3005	Value->getBeginLoc(), Value->getBeginLoc());
3006
3007	InitializationSequence Seq(S, Entity, Kind, InitExpr);
3008
3009	if (!Seq)
3010	return;
3011
3012	for (const InitializationSequence::Step &Step : Seq.steps()) {
3013	if (Step.Kind != InitializationSequence::SK_ConstructorInitialization &&
3014	Step.Kind != InitializationSequence::SK_UserConversion)
3015	continue;
3016
3017	FunctionDecl *FD = Step.Function.Function;
3018	if (ConvertingConstructorsOnly) {
3019	if (isa<CXXConstructorDecl>(FD)) {
3020	// C++14 [class.copy]p32:
3021	// [...] If the first overload resolution fails or was not performed,
3022	// or if the type of the first parameter of the selected constructor
3023	// is not an rvalue reference to the object's type (possibly
3024	// cv-qualified), overload resolution is performed again, considering
3025	// the object as an lvalue.
3026	const RValueReferenceType *RRefType =
3027	FD->getParamDecl(0)->getType()->getAs<RValueReferenceType>();
3028	if (!RRefType)
3029	break;
3030	if (!S.Context.hasSameUnqualifiedType(RRefType->getPointeeType(),
3031	NRVOCandidate->getType()))
3032	break;
3033	} else {
3034	continue;
3035	}
3036	} else {
3037	if (isa<CXXConstructorDecl>(FD)) {
3038	// Check that overload resolution selected a constructor taking an
3039	// rvalue reference. If it selected an lvalue reference, then we
3040	// didn't need to cast this thing to an rvalue in the first place.
3041	if (!isa<RValueReferenceType>(FD->getParamDecl(0)->getType()))
3042	break;
3043	} else if (isa<CXXMethodDecl>(FD)) {
3044	// Check that overload resolution selected a conversion operator
3045	// taking an rvalue reference.
3046	if (cast<CXXMethodDecl>(FD)->getRefQualifier() != RQ_RValue)
3047	break;
3048	} else {
3049	continue;
3050	}
3051	}
3052
3053	// Promote "AsRvalue" to the heap, since we now need this
3054	// expression node to persist.
3055	Value = ImplicitCastExpr::Create(S.Context, Value->getType(), CK_NoOp,
3056	Value, nullptr, VK_XValue);
3057
3058	// Complete type-checking the initialization of the return type
3059	// using the constructor we found.
3060	Res = Seq.Perform(S, Entity, Kind, Value);
3061	}
3062	}
3063
3064	/// Perform the initialization of a potentially-movable value, which
3065	/// is the result of return value.
3066	///
3067	/// This routine implements C++14 [class.copy]p32, which attempts to treat
3068	/// returned lvalues as rvalues in certain cases (to prefer move construction),
3069	/// then falls back to treating them as lvalues if that failed.
3070	ExprResult
3071	Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
3072	const VarDecl *NRVOCandidate,
3073	QualType ResultType,
3074	Expr *Value,
3075	bool AllowNRVO) {
3076	// C++14 [class.copy]p32:
3077	// When the criteria for elision of a copy/move operation are met, but not for
3078	// an exception-declaration, and the object to be copied is designated by an
3079	// lvalue, or when the expression in a return statement is a (possibly
3080	// parenthesized) id-expression that names an object with automatic storage
3081	// duration declared in the body or parameter-declaration-clause of the
3082	// innermost enclosing function or lambda-expression, overload resolution to
3083	// select the constructor for the copy is first performed as if the object
3084	// were designated by an rvalue.
3085	ExprResult Res = ExprError();
3086
3087	if (AllowNRVO) {
3088	bool AffectedByCWG1579 = false;
3089
3090	if (!NRVOCandidate) {
3091	NRVOCandidate = getCopyElisionCandidate(ResultType, Value, CES_Default);
3092	if (NRVOCandidate &&
3093	!getDiagnostics().isIgnored(diag::warn_return_std_move_in_cxx11,
3094	Value->getExprLoc())) {
3095	const VarDecl *NRVOCandidateInCXX11 =
3096	getCopyElisionCandidate(ResultType, Value, CES_FormerDefault);
3097	AffectedByCWG1579 = (!NRVOCandidateInCXX11);
3098	}
3099	}
3100
3101	if (NRVOCandidate) {
3102	TryMoveInitialization(*this, Entity, NRVOCandidate, ResultType, Value,
3103	true, Res);
3104	}
3105
3106	if (!Res.isInvalid() && AffectedByCWG1579) {
3107	QualType QT = NRVOCandidate->getType();
3108	if (QT.getNonReferenceType()
3109	.getUnqualifiedType()
3110	.isTriviallyCopyableType(Context)) {
3111	// Adding 'std::move' around a trivially copyable variable is probably
3112	// pointless. Don't suggest it.
3113	} else {
3114	// Common cases for this are returning unique_ptr<Derived> from a
3115	// function of return type unique_ptr<Base>, or returning T from a
3116	// function of return type Expected<T>. This is totally fine in a
3117	// post-CWG1579 world, but was not fine before.
3118	assert(!ResultType.isNull());
3119	SmallString<32> Str;
3120	Str += "std::move(";
3121	Str += NRVOCandidate->getDeclName().getAsString();
3122	Str += ")";
3123	Diag(Value->getExprLoc(), diag::warn_return_std_move_in_cxx11)
3124	<< Value->getSourceRange()
3125	<< NRVOCandidate->getDeclName() << ResultType << QT;
3126	Diag(Value->getExprLoc(), diag::note_add_std_move_in_cxx11)
3127	<< FixItHint::CreateReplacement(Value->getSourceRange(), Str);
3128	}
3129	} else if (Res.isInvalid() &&
3130	!getDiagnostics().isIgnored(diag::warn_return_std_move,
3131	Value->getExprLoc())) {
3132	const VarDecl *FakeNRVOCandidate =
3133	getCopyElisionCandidate(QualType(), Value, CES_AsIfByStdMove);
3134	if (FakeNRVOCandidate) {
3135	QualType QT = FakeNRVOCandidate->getType();
3136	if (QT->isLValueReferenceType()) {
3137	// Adding 'std::move' around an lvalue reference variable's name is
3138	// dangerous. Don't suggest it.
3139	} else if (QT.getNonReferenceType()
3140	.getUnqualifiedType()
3141	.isTriviallyCopyableType(Context)) {
3142	// Adding 'std::move' around a trivially copyable variable is probably
3143	// pointless. Don't suggest it.
3144	} else {
3145	ExprResult FakeRes = ExprError();
3146	Expr *FakeValue = Value;
3147	TryMoveInitialization(*this, Entity, FakeNRVOCandidate, ResultType,
3148	FakeValue, false, FakeRes);
3149	if (!FakeRes.isInvalid()) {
3150	bool IsThrow =
3151	(Entity.getKind() == InitializedEntity::EK_Exception);
3152	SmallString<32> Str;
3153	Str += "std::move(";
3154	Str += FakeNRVOCandidate->getDeclName().getAsString();
3155	Str += ")";
3156	Diag(Value->getExprLoc(), diag::warn_return_std_move)
3157	<< Value->getSourceRange()
3158	<< FakeNRVOCandidate->getDeclName() << IsThrow;
3159	Diag(Value->getExprLoc(), diag::note_add_std_move)
3160	<< FixItHint::CreateReplacement(Value->getSourceRange(), Str);
3161	}
3162	}
3163	}
3164	}
3165	}
3166
3167	// Either we didn't meet the criteria for treating an lvalue as an rvalue,
3168	// above, or overload resolution failed. Either way, we need to try
3169	// (again) now with the return value expression as written.
3170	if (Res.isInvalid())
3171	Res = PerformCopyInitialization(Entity, SourceLocation(), Value);
3172
3173	return Res;
3174	}
3175
3176	/// Determine whether the declared return type of the specified function
3177	/// contains 'auto'.
3178	static bool hasDeducedReturnType(FunctionDecl *FD) {
3179	const FunctionProtoType *FPT =
3180	FD->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>();
3181	return FPT->getReturnType()->isUndeducedType();
3182	}
3183
3184	/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements
3185	/// for capturing scopes.
3186	///
3187	StmtResult
3188	Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
3189	// If this is the first return we've seen, infer the return type.
3190	// [expr.prim.lambda]p4 in C++11; block literals follow the same rules.
3191	CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction());
3192	QualType FnRetType = CurCap->ReturnType;
3193	LambdaScopeInfo *CurLambda = dyn_cast<LambdaScopeInfo>(CurCap);
3194	bool HasDeducedReturnType =
3195	CurLambda && hasDeducedReturnType(CurLambda->CallOperator);
3196
3197	if (ExprEvalContexts.back().Context ==
3198	ExpressionEvaluationContext::DiscardedStatement &&
3199	(HasDeducedReturnType \|\| CurCap->HasImplicitReturnType)) {
3200	if (RetValExp) {
3201	ExprResult ER =
3202	ActOnFinishFullExpr(RetValExp, ReturnLoc, /DiscardedValue/ false);
3203	if (ER.isInvalid())
3204	return StmtError();
3205	RetValExp = ER.get();
3206	}
3207	return ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3208	/* NRVOCandidate=*/nullptr);
3209	}
3210
3211	if (HasDeducedReturnType) {
3212	// In C++1y, the return type may involve 'auto'.
3213	// FIXME: Blocks might have a return type of 'auto' explicitly specified.
3214	FunctionDecl *FD = CurLambda->CallOperator;
3215	if (CurCap->ReturnType.isNull())
3216	CurCap->ReturnType = FD->getReturnType();
3217
3218	AutoType *AT = CurCap->ReturnType->getContainedAutoType();
3219	(0) . __assert_fail ("AT && \"lost auto type from lambda return type\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 3219, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(AT && "lost auto type from lambda return type");
3220	if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
3221	FD->setInvalidDecl();
3222	return StmtError();
3223	}
3224	CurCap->ReturnType = FnRetType = FD->getReturnType();
3225	} else if (CurCap->HasImplicitReturnType) {
3226	// For blocks/lambdas with implicit return types, we check each return
3227	// statement individually, and deduce the common return type when the block
3228	// or lambda is completed.
3229	// FIXME: Fold this into the 'auto' codepath above.
3230	if (RetValExp && !isa<InitListExpr>(RetValExp)) {
3231	ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp);
3232	if (Result.isInvalid())
3233	return StmtError();
3234	RetValExp = Result.get();
3235
3236	// DR1048: even prior to C++14, we should use the 'auto' deduction rules
3237	// when deducing a return type for a lambda-expression (or by extension
3238	// for a block). These rules differ from the stated C++11 rules only in
3239	// that they remove top-level cv-qualifiers.
3240	if (!CurContext->isDependentContext())
3241	FnRetType = RetValExp->getType().getUnqualifiedType();
3242	else
3243	FnRetType = CurCap->ReturnType = Context.DependentTy;
3244	} else {
3245	if (RetValExp) {
3246	// C++11 [expr.lambda.prim]p4 bans inferring the result from an
3247	// initializer list, because it is not an expression (even
3248	// though we represent it as one). We still deduce 'void'.
3249	Diag(ReturnLoc, diag::err_lambda_return_init_list)
3250	<< RetValExp->getSourceRange();
3251	}
3252
3253	FnRetType = Context.VoidTy;
3254	}
3255
3256	// Although we'll properly infer the type of the block once it's completed,
3257	// make sure we provide a return type now for better error recovery.
3258	if (CurCap->ReturnType.isNull())
3259	CurCap->ReturnType = FnRetType;
3260	}
3261	assert(!FnRetType.isNull());
3262
3263	if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) {
3264	if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) {
3265	Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr);
3266	return StmtError();
3267	}
3268	} else if (CapturedRegionScopeInfo *CurRegion =
3269	dyn_cast<CapturedRegionScopeInfo>(CurCap)) {
3270	Diag(ReturnLoc, diag::err_return_in_captured_stmt) << CurRegion->getRegionName();
3271	return StmtError();
3272	} else {
3273	(0) . __assert_fail ("CurLambda && \"unknown kind of captured scope\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 3273, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(CurLambda && "unknown kind of captured scope");
3274	if (CurLambda->CallOperator->getType()->getAs<FunctionType>()
3275	->getNoReturnAttr()) {
3276	Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr);
3277	return StmtError();
3278	}
3279	}
3280
3281	// Otherwise, verify that this result type matches the previous one. We are
3282	// pickier with blocks than for normal functions because we don't have GCC
3283	// compatibility to worry about here.
3284	const VarDecl *NRVOCandidate = nullptr;
3285	if (FnRetType->isDependentType()) {
3286	// Delay processing for now. TODO: there are lots of dependent
3287	// types we can conclusively prove aren't void.
3288	} else if (FnRetType->isVoidType()) {
3289	if (RetValExp && !isa<InitListExpr>(RetValExp) &&
3290	!(getLangOpts().CPlusPlus &&
3291	(RetValExp->isTypeDependent() \|\|
3292	RetValExp->getType()->isVoidType()))) {
3293	if (!getLangOpts().CPlusPlus &&
3294	RetValExp->getType()->isVoidType())
3295	Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2;
3296	else {
3297	Diag(ReturnLoc, diag::err_return_block_has_expr);
3298	RetValExp = nullptr;
3299	}
3300	}
3301	} else if (!RetValExp) {
3302	return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
3303	} else if (!RetValExp->isTypeDependent()) {
3304	// we have a non-void block with an expression, continue checking
3305
3306	// C99 6.8.6.4p3(136): The return statement is not an assignment. The
3307	// overlap restriction of subclause 6.5.16.1 does not apply to the case of
3308	// function return.
3309
3310	// In C++ the return statement is handled via a copy initialization.
3311	// the C version of which boils down to CheckSingleAssignmentConstraints.
3312	NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
3313	InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
3314	FnRetType,
3315	NRVOCandidate != nullptr);
3316	ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
3317	FnRetType, RetValExp);
3318	if (Res.isInvalid()) {
3319	// FIXME: Cleanup temporaries here, anyway?
3320	return StmtError();
3321	}
3322	RetValExp = Res.get();
3323	CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc);
3324	} else {
3325	NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
3326	}
3327
3328	if (RetValExp) {
3329	ExprResult ER =
3330	ActOnFinishFullExpr(RetValExp, ReturnLoc, /DiscardedValue/ false);
3331	if (ER.isInvalid())
3332	return StmtError();
3333	RetValExp = ER.get();
3334	}
3335	auto *Result =
3336	ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate);
3337
3338	// If we need to check for the named return value optimization,
3339	// or if we need to infer the return type,
3340	// save the return statement in our scope for later processing.
3341	if (CurCap->HasImplicitReturnType \|\| NRVOCandidate)
3342	FunctionScopes.back()->Returns.push_back(Result);
3343
3344	if (FunctionScopes.back()->FirstReturnLoc.isInvalid())
3345	FunctionScopes.back()->FirstReturnLoc = ReturnLoc;
3346
3347	return Result;
3348	}
3349
3350	namespace {
3351	/// Marks all typedefs in all local classes in a type referenced.
3352	///
3353	/// In a function like
3354	/// auto f() {
3355	/// struct S { typedef int a; };
3356	/// return S();
3357	/// }
3358	///
3359	/// the local type escapes and could be referenced in some TUs but not in
3360	/// others. Pretend that all local typedefs are always referenced, to not warn
3361	/// on this. This isn't necessary if f has internal linkage, or the typedef
3362	/// is private.
3363	class LocalTypedefNameReferencer
3364	: public RecursiveASTVisitor<LocalTypedefNameReferencer> {
3365	public:
3366	LocalTypedefNameReferencer(Sema &S) : S(S) {}
3367	bool VisitRecordType(const RecordType *RT);
3368	private:
3369	Sema &S;
3370	};
3371	bool LocalTypedefNameReferencer::VisitRecordType(const RecordType *RT) {
3372	auto *R = dyn_cast<CXXRecordDecl>(RT->getDecl());
3373	if (!R \|\| !R->isLocalClass() \|\| !R->isLocalClass()->isExternallyVisible() \|\|
3374	R->isDependentType())
3375	return true;
3376	for (auto *TmpD : R->decls())
3377	if (auto *T = dyn_cast<TypedefNameDecl>(TmpD))
3378	if (T->getAccess() != AS_private \|\| R->hasFriends())
3379	S.MarkAnyDeclReferenced(T->getLocation(), T, /OdrUse=/false);
3380	return true;
3381	}
3382	}
3383
3384	TypeLoc Sema::getReturnTypeLoc(FunctionDecl *FD) const {
3385	TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc().IgnoreParens();
3386	while (auto ATL = TL.getAs<AttributedTypeLoc>())
3387	TL = ATL.getModifiedLoc().IgnoreParens();
3388	return TL.castAs<FunctionProtoTypeLoc>().getReturnLoc();
3389	}
3390
3391	/// Deduce the return type for a function from a returned expression, per
3392	/// C++1y [dcl.spec.auto]p6.
3393	bool Sema::DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD,
3394	SourceLocation ReturnLoc,
3395	Expr *&RetExpr,
3396	AutoType *AT) {
3397	// If this is the conversion function for a lambda, we choose to deduce it
3398	// type from the corresponding call operator, not from the synthesized return
3399	// statement within it. See Sema::DeduceReturnType.
3400	if (isLambdaConversionOperator(FD))
3401	return false;
3402
3403	TypeLoc OrigResultType = getReturnTypeLoc(FD);
3404	QualType Deduced;
3405
3406	if (RetExpr && isa<InitListExpr>(RetExpr)) {
3407	// If the deduction is for a return statement and the initializer is
3408	// a braced-init-list, the program is ill-formed.
3409	Diag(RetExpr->getExprLoc(),
3410	getCurLambda() ? diag::err_lambda_return_init_list
3411	: diag::err_auto_fn_return_init_list)
3412	<< RetExpr->getSourceRange();
3413	return true;
3414	}
3415
3416	if (FD->isDependentContext()) {
3417	// C++1y [dcl.spec.auto]p12:
3418	// Return type deduction [...] occurs when the definition is
3419	// instantiated even if the function body contains a return
3420	// statement with a non-type-dependent operand.
3421	(0) . __assert_fail ("AT->isDeduced() && \"should have deduced to dependent type\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 3421, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(AT->isDeduced() && "should have deduced to dependent type");
3422	return false;
3423	}
3424
3425	if (RetExpr) {
3426	// Otherwise, [...] deduce a value for U using the rules of template
3427	// argument deduction.
3428	DeduceAutoResult DAR = DeduceAutoType(OrigResultType, RetExpr, Deduced);
3429
3430	if (DAR == DAR_Failed && !FD->isInvalidDecl())
3431	Diag(RetExpr->getExprLoc(), diag::err_auto_fn_deduction_failure)
3432	<< OrigResultType.getType() << RetExpr->getType();
3433
3434	if (DAR != DAR_Succeeded)
3435	return true;
3436
3437	// If a local type is part of the returned type, mark its fields as
3438	// referenced.
3439	LocalTypedefNameReferencer Referencer(*this);
3440	Referencer.TraverseType(RetExpr->getType());
3441	} else {
3442	// In the case of a return with no operand, the initializer is considered
3443	// to be void().
3444	//
3445	// Deduction here can only succeed if the return type is exactly 'cv auto'
3446	// or 'decltype(auto)', so just check for that case directly.
3447	if (!OrigResultType.getType()->getAs<AutoType>()) {
3448	Diag(ReturnLoc, diag::err_auto_fn_return_void_but_not_auto)
3449	<< OrigResultType.getType();
3450	return true;
3451	}
3452	// We always deduce U = void in this case.
3453	Deduced = SubstAutoType(OrigResultType.getType(), Context.VoidTy);
3454	if (Deduced.isNull())
3455	return true;
3456	}
3457
3458	// If a function with a declared return type that contains a placeholder type
3459	// has multiple return statements, the return type is deduced for each return
3460	// statement. [...] if the type deduced is not the same in each deduction,
3461	// the program is ill-formed.
3462	QualType DeducedT = AT->getDeducedType();
3463	if (!DeducedT.isNull() && !FD->isInvalidDecl()) {
3464	AutoType *NewAT = Deduced->getContainedAutoType();
3465	// It is possible that NewAT->getDeducedType() is null. When that happens,
3466	// we should not crash, instead we ignore this deduction.
3467	if (NewAT->getDeducedType().isNull())
3468	return false;
3469
3470	CanQualType OldDeducedType = Context.getCanonicalFunctionResultType(
3471	DeducedT);
3472	CanQualType NewDeducedType = Context.getCanonicalFunctionResultType(
3473	NewAT->getDeducedType());
3474	if (!FD->isDependentContext() && OldDeducedType != NewDeducedType) {
3475	const LambdaScopeInfo *LambdaSI = getCurLambda();
3476	if (LambdaSI && LambdaSI->HasImplicitReturnType) {
3477	Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible)
3478	<< NewAT->getDeducedType() << DeducedT
3479	<< true /IsLambda/;
3480	} else {
3481	Diag(ReturnLoc, diag::err_auto_fn_different_deductions)
3482	<< (AT->isDecltypeAuto() ? 1 : 0)
3483	<< NewAT->getDeducedType() << DeducedT;
3484	}
3485	return true;
3486	}
3487	} else if (!FD->isInvalidDecl()) {
3488	// Update all declarations of the function to have the deduced return type.
3489	Context.adjustDeducedFunctionResultType(FD, Deduced);
3490	}
3491
3492	return false;
3493	}
3494
3495	StmtResult
3496	Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
3497	Scope *CurScope) {
3498	StmtResult R = BuildReturnStmt(ReturnLoc, RetValExp);
3499	if (R.isInvalid() \|\| ExprEvalContexts.back().Context ==
3500	ExpressionEvaluationContext::DiscardedStatement)
3501	return R;
3502
3503	if (VarDecl *VD =
3504	const_cast<VarDecl*>(cast<ReturnStmt>(R.get())->getNRVOCandidate())) {
3505	CurScope->addNRVOCandidate(VD);
3506	} else {
3507	CurScope->setNoNRVO();
3508	}
3509
3510	CheckJumpOutOfSEHFinally(this, ReturnLoc, CurScope->getFnParent());
3511
3512	return R;
3513	}
3514
3515	StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
3516	// Check for unexpanded parameter packs.
3517	if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp))
3518	return StmtError();
3519
3520	if (isa<CapturingScopeInfo>(getCurFunction()))
3521	return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp);
3522
3523	QualType FnRetType;
3524	QualType RelatedRetType;
3525	const AttrVec *Attrs = nullptr;
3526	bool isObjCMethod = false;
3527
3528	if (const FunctionDecl *FD = getCurFunctionDecl()) {
3529	FnRetType = FD->getReturnType();
3530	if (FD->hasAttrs())
3531	Attrs = &FD->getAttrs();
3532	if (FD->isNoReturn())
3533	Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
3534	<< FD->getDeclName();
3535	if (FD->isMain() && RetValExp)
3536	if (isa<CXXBoolLiteralExpr>(RetValExp))
3537	Diag(ReturnLoc, diag::warn_main_returns_bool_literal)
3538	<< RetValExp->getSourceRange();
3539	} else if (ObjCMethodDecl *MD = getCurMethodDecl()) {
3540	FnRetType = MD->getReturnType();
3541	isObjCMethod = true;
3542	if (MD->hasAttrs())
3543	Attrs = &MD->getAttrs();
3544	if (MD->hasRelatedResultType() && MD->getClassInterface()) {
3545	// In the implementation of a method with a related return type, the
3546	// type used to type-check the validity of return statements within the
3547	// method body is a pointer to the type of the class being implemented.
3548	RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface());
3549	RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType);
3550	}
3551	} else // If we don't have a function/method context, bail.
3552	return StmtError();
3553
3554	// C++1z: discarded return statements are not considered when deducing a
3555	// return type.
3556	if (ExprEvalContexts.back().Context ==
3557	ExpressionEvaluationContext::DiscardedStatement &&
3558	FnRetType->getContainedAutoType()) {
3559	if (RetValExp) {
3560	ExprResult ER =
3561	ActOnFinishFullExpr(RetValExp, ReturnLoc, /DiscardedValue/ false);
3562	if (ER.isInvalid())
3563	return StmtError();
3564	RetValExp = ER.get();
3565	}
3566	return ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3567	/* NRVOCandidate=*/nullptr);
3568	}
3569
3570	// FIXME: Add a flag to the ScopeInfo to indicate whether we're performing
3571	// deduction.
3572	if (getLangOpts().CPlusPlus14) {
3573	if (AutoType *AT = FnRetType->getContainedAutoType()) {
3574	FunctionDecl *FD = cast<FunctionDecl>(CurContext);
3575	if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
3576	FD->setInvalidDecl();
3577	return StmtError();
3578	} else {
3579	FnRetType = FD->getReturnType();
3580	}
3581	}
3582	}
3583
3584	bool HasDependentReturnType = FnRetType->isDependentType();
3585
3586	ReturnStmt *Result = nullptr;
3587	if (FnRetType->isVoidType()) {
3588	if (RetValExp) {
3589	if (isa<InitListExpr>(RetValExp)) {
3590	// We simply never allow init lists as the return value of void
3591	// functions. This is compatible because this was never allowed before,
3592	// so there's no legacy code to deal with.
3593	NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3594	int FunctionKind = 0;
3595	if (isa<ObjCMethodDecl>(CurDecl))
3596	FunctionKind = 1;
3597	else if (isa<CXXConstructorDecl>(CurDecl))
3598	FunctionKind = 2;
3599	else if (isa<CXXDestructorDecl>(CurDecl))
3600	FunctionKind = 3;
3601
3602	Diag(ReturnLoc, diag::err_return_init_list)
3603	<< CurDecl->getDeclName() << FunctionKind
3604	<< RetValExp->getSourceRange();
3605
3606	// Drop the expression.
3607	RetValExp = nullptr;
3608	} else if (!RetValExp->isTypeDependent()) {
3609	// C99 6.8.6.4p1 (ext_ since GCC warns)
3610	unsigned D = diag::ext_return_has_expr;
3611	if (RetValExp->getType()->isVoidType()) {
3612	NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3613	if (isa<CXXConstructorDecl>(CurDecl) \|\|
3614	isa<CXXDestructorDecl>(CurDecl))
3615	D = diag::err_ctor_dtor_returns_void;
3616	else
3617	D = diag::ext_return_has_void_expr;
3618	}
3619	else {
3620	ExprResult Result = RetValExp;
3621	Result = IgnoredValueConversions(Result.get());
3622	if (Result.isInvalid())
3623	return StmtError();
3624	RetValExp = Result.get();
3625	RetValExp = ImpCastExprToType(RetValExp,
3626	Context.VoidTy, CK_ToVoid).get();
3627	}
3628	// return of void in constructor/destructor is illegal in C++.
3629	if (D == diag::err_ctor_dtor_returns_void) {
3630	NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3631	Diag(ReturnLoc, D)
3632	<< CurDecl->getDeclName() << isa<CXXDestructorDecl>(CurDecl)
3633	<< RetValExp->getSourceRange();
3634	}
3635	// return (some void expression); is legal in C++.
3636	else if (D != diag::ext_return_has_void_expr \|\|
3637	!getLangOpts().CPlusPlus) {
3638	NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3639
3640	int FunctionKind = 0;
3641	if (isa<ObjCMethodDecl>(CurDecl))
3642	FunctionKind = 1;
3643	else if (isa<CXXConstructorDecl>(CurDecl))
3644	FunctionKind = 2;
3645	else if (isa<CXXDestructorDecl>(CurDecl))
3646	FunctionKind = 3;
3647
3648	Diag(ReturnLoc, D)
3649	<< CurDecl->getDeclName() << FunctionKind
3650	<< RetValExp->getSourceRange();
3651	}
3652	}
3653
3654	if (RetValExp) {
3655	ExprResult ER =
3656	ActOnFinishFullExpr(RetValExp, ReturnLoc, /DiscardedValue/ false);
3657	if (ER.isInvalid())
3658	return StmtError();
3659	RetValExp = ER.get();
3660	}
3661	}
3662
3663	Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3664	/* NRVOCandidate=*/nullptr);
3665	} else if (!RetValExp && !HasDependentReturnType) {
3666	FunctionDecl *FD = getCurFunctionDecl();
3667
3668	unsigned DiagID;
3669	if (getLangOpts().CPlusPlus11 && FD && FD->isConstexpr()) {
3670	// C++11 [stmt.return]p2
3671	DiagID = diag::err_constexpr_return_missing_expr;
3672	FD->setInvalidDecl();
3673	} else if (getLangOpts().C99) {
3674	// C99 6.8.6.4p1 (ext_ since GCC warns)
3675	DiagID = diag::ext_return_missing_expr;
3676	} else {
3677	// C90 6.6.6.4p4
3678	DiagID = diag::warn_return_missing_expr;
3679	}
3680
3681	if (FD)
3682	Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/fn/;
3683	else
3684	Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/meth/;
3685
3686	Result = ReturnStmt::Create(Context, ReturnLoc, /* RetExpr=*/nullptr,
3687	/* NRVOCandidate=*/nullptr);
3688	} else {
3689	assert(RetValExp \|\| HasDependentReturnType);
3690	const VarDecl *NRVOCandidate = nullptr;
3691
3692	QualType RetType = RelatedRetType.isNull() ? FnRetType : RelatedRetType;
3693
3694	// C99 6.8.6.4p3(136): The return statement is not an assignment. The
3695	// overlap restriction of subclause 6.5.16.1 does not apply to the case of
3696	// function return.
3697
3698	// In C++ the return statement is handled via a copy initialization,
3699	// the C version of which boils down to CheckSingleAssignmentConstraints.
3700	if (RetValExp)
3701	NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
3702	if (!HasDependentReturnType && !RetValExp->isTypeDependent()) {
3703	// we have a non-void function with an expression, continue checking
3704	InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
3705	RetType,
3706	NRVOCandidate != nullptr);
3707	ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
3708	RetType, RetValExp);
3709	if (Res.isInvalid()) {
3710	// FIXME: Clean up temporaries here anyway?
3711	return StmtError();
3712	}
3713	RetValExp = Res.getAs<Expr>();
3714
3715	// If we have a related result type, we need to implicitly
3716	// convert back to the formal result type. We can't pretend to
3717	// initialize the result again --- we might end double-retaining
3718	// --- so instead we initialize a notional temporary.
3719	if (!RelatedRetType.isNull()) {
3720	Entity = InitializedEntity::InitializeRelatedResult(getCurMethodDecl(),
3721	FnRetType);
3722	Res = PerformCopyInitialization(Entity, ReturnLoc, RetValExp);
3723	if (Res.isInvalid()) {
3724	// FIXME: Clean up temporaries here anyway?
3725	return StmtError();
3726	}
3727	RetValExp = Res.getAs<Expr>();
3728	}
3729
3730	CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc, isObjCMethod, Attrs,
3731	getCurFunctionDecl());
3732	}
3733
3734	if (RetValExp) {
3735	ExprResult ER =
3736	ActOnFinishFullExpr(RetValExp, ReturnLoc, /DiscardedValue/ false);
3737	if (ER.isInvalid())
3738	return StmtError();
3739	RetValExp = ER.get();
3740	}
3741	Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate);
3742	}
3743
3744	// If we need to check for the named return value optimization, save the
3745	// return statement in our scope for later processing.
3746	if (Result->getNRVOCandidate())
3747	FunctionScopes.back()->Returns.push_back(Result);
3748
3749	if (FunctionScopes.back()->FirstReturnLoc.isInvalid())
3750	FunctionScopes.back()->FirstReturnLoc = ReturnLoc;
3751
3752	return Result;
3753	}
3754
3755	StmtResult
3756	Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
3757	SourceLocation RParen, Decl *Parm,
3758	Stmt *Body) {
3759	VarDecl *Var = cast_or_null<VarDecl>(Parm);
3760	if (Var && Var->isInvalidDecl())
3761	return StmtError();
3762
3763	return new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body);
3764	}
3765
3766	StmtResult
3767	Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) {
3768	return new (Context) ObjCAtFinallyStmt(AtLoc, Body);
3769	}
3770
3771	StmtResult
3772	Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
3773	MultiStmtArg CatchStmts, Stmt *Finally) {
3774	if (!getLangOpts().ObjCExceptions)
3775	Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try";
3776
3777	setFunctionHasBranchProtectedScope();
3778	unsigned NumCatchStmts = CatchStmts.size();
3779	return ObjCAtTryStmt::Create(Context, AtLoc, Try, CatchStmts.data(),
3780	NumCatchStmts, Finally);
3781	}
3782
3783	StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) {
3784	if (Throw) {
3785	ExprResult Result = DefaultLvalueConversion(Throw);
3786	if (Result.isInvalid())
3787	return StmtError();
3788
3789	Result = ActOnFinishFullExpr(Result.get(), /DiscardedValue/ false);
3790	if (Result.isInvalid())
3791	return StmtError();
3792	Throw = Result.get();
3793
3794	QualType ThrowType = Throw->getType();
3795	// Make sure the expression type is an ObjC pointer or "void *".
3796	if (!ThrowType->isDependentType() &&
3797	!ThrowType->isObjCObjectPointerType()) {
3798	const PointerType *PT = ThrowType->getAs<PointerType>();
3799	if (!PT \|\| !PT->getPointeeType()->isVoidType())
3800	return StmtError(Diag(AtLoc, diag::err_objc_throw_expects_object)
3801	<< Throw->getType() << Throw->getSourceRange());
3802	}
3803	}
3804
3805	return new (Context) ObjCAtThrowStmt(AtLoc, Throw);
3806	}
3807
3808	StmtResult
3809	Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
3810	Scope *CurScope) {
3811	if (!getLangOpts().ObjCExceptions)
3812	Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw";
3813
3814	if (!Throw) {
3815	// @throw without an expression designates a rethrow (which must occur
3816	// in the context of an @catch clause).
3817	Scope *AtCatchParent = CurScope;
3818	while (AtCatchParent && !AtCatchParent->isAtCatchScope())
3819	AtCatchParent = AtCatchParent->getParent();
3820	if (!AtCatchParent)
3821	return StmtError(Diag(AtLoc, diag::err_rethrow_used_outside_catch));
3822	}
3823	return BuildObjCAtThrowStmt(AtLoc, Throw);
3824	}
3825
3826	ExprResult
3827	Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) {
3828	ExprResult result = DefaultLvalueConversion(operand);
3829	if (result.isInvalid())
3830	return ExprError();
3831	operand = result.get();
3832
3833	// Make sure the expression type is an ObjC pointer or "void *".
3834	QualType type = operand->getType();
3835	if (!type->isDependentType() &&
3836	!type->isObjCObjectPointerType()) {
3837	const PointerType *pointerType = type->getAs<PointerType>();
3838	if (!pointerType \|\| !pointerType->getPointeeType()->isVoidType()) {
3839	if (getLangOpts().CPlusPlus) {
3840	if (RequireCompleteType(atLoc, type,
3841	diag::err_incomplete_receiver_type))
3842	return Diag(atLoc, diag::err_objc_synchronized_expects_object)
3843	<< type << operand->getSourceRange();
3844
3845	ExprResult result = PerformContextuallyConvertToObjCPointer(operand);
3846	if (result.isInvalid())
3847	return ExprError();
3848	if (!result.isUsable())
3849	return Diag(atLoc, diag::err_objc_synchronized_expects_object)
3850	<< type << operand->getSourceRange();
3851
3852	operand = result.get();
3853	} else {
3854	return Diag(atLoc, diag::err_objc_synchronized_expects_object)
3855	<< type << operand->getSourceRange();
3856	}
3857	}
3858	}
3859
3860	// The operand to @synchronized is a full-expression.
3861	return ActOnFinishFullExpr(operand, /DiscardedValue/ false);
3862	}
3863
3864	StmtResult
3865	Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr,
3866	Stmt *SyncBody) {
3867	// We can't jump into or indirect-jump out of a @synchronized block.
3868	setFunctionHasBranchProtectedScope();
3869	return new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody);
3870	}
3871
3872	/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
3873	/// and creates a proper catch handler from them.
3874	StmtResult
3875	Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl,
3876	Stmt *HandlerBlock) {
3877	// There's nothing to test that ActOnExceptionDecl didn't already test.
3878	return new (Context)
3879	CXXCatchStmt(CatchLoc, cast_or_null<VarDecl>(ExDecl), HandlerBlock);
3880	}
3881
3882	StmtResult
3883	Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) {
3884	setFunctionHasBranchProtectedScope();
3885	return new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body);
3886	}
3887
3888	namespace {
3889	class CatchHandlerType {
3890	QualType QT;
3891	unsigned IsPointer : 1;
3892
3893	// This is a special constructor to be used only with DenseMapInfo's
3894	// getEmptyKey() and getTombstoneKey() functions.
3895	friend struct llvm::DenseMapInfo<CatchHandlerType>;
3896	enum Unique { ForDenseMap };
3897	CatchHandlerType(QualType QT, Unique) : QT(QT), IsPointer(false) {}
3898
3899	public:
3900	/// Used when creating a CatchHandlerType from a handler type; will determine
3901	/// whether the type is a pointer or reference and will strip off the top
3902	/// level pointer and cv-qualifiers.
3903	CatchHandlerType(QualType Q) : QT(Q), IsPointer(false) {
3904	if (QT->isPointerType())
3905	IsPointer = true;
3906
3907	if (IsPointer \|\| QT->isReferenceType())
3908	QT = QT->getPointeeType();
3909	QT = QT.getUnqualifiedType();
3910	}
3911
3912	/// Used when creating a CatchHandlerType from a base class type; pretends the
3913	/// type passed in had the pointer qualifier, does not need to get an
3914	/// unqualified type.
3915	CatchHandlerType(QualType QT, bool IsPointer)
3916	: QT(QT), IsPointer(IsPointer) {}
3917
3918	QualType underlying() const { return QT; }
3919	bool isPointer() const { return IsPointer; }
3920
3921	friend bool operator==(const CatchHandlerType &LHS,
3922	const CatchHandlerType &RHS) {
3923	// If the pointer qualification does not match, we can return early.
3924	if (LHS.IsPointer != RHS.IsPointer)
3925	return false;
3926	// Otherwise, check the underlying type without cv-qualifiers.
3927	return LHS.QT == RHS.QT;
3928	}
3929	};
3930	} // namespace
3931
3932	namespace llvm {
3933	template <> struct DenseMapInfo<CatchHandlerType> {
3934	static CatchHandlerType getEmptyKey() {
3935	return CatchHandlerType(DenseMapInfo<QualType>::getEmptyKey(),
3936	CatchHandlerType::ForDenseMap);
3937	}
3938
3939	static CatchHandlerType getTombstoneKey() {
3940	return CatchHandlerType(DenseMapInfo<QualType>::getTombstoneKey(),
3941	CatchHandlerType::ForDenseMap);
3942	}
3943
3944	static unsigned getHashValue(const CatchHandlerType &Base) {
3945	return DenseMapInfo<QualType>::getHashValue(Base.underlying());
3946	}
3947
3948	static bool isEqual(const CatchHandlerType &LHS,
3949	const CatchHandlerType &RHS) {
3950	return LHS == RHS;
3951	}
3952	};
3953	}
3954
3955	namespace {
3956	class CatchTypePublicBases {
3957	ASTContext &Ctx;
3958	const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &TypesToCheck;
3959	const bool CheckAgainstPointer;
3960
3961	CXXCatchStmt *FoundHandler;
3962	CanQualType FoundHandlerType;
3963
3964	public:
3965	CatchTypePublicBases(
3966	ASTContext &Ctx,
3967	const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &T, bool C)
3968	: Ctx(Ctx), TypesToCheck(T), CheckAgainstPointer(C),
3969	FoundHandler(nullptr) {}
3970
3971	CXXCatchStmt *getFoundHandler() const { return FoundHandler; }
3972	CanQualType getFoundHandlerType() const { return FoundHandlerType; }
3973
3974	bool operator()(const CXXBaseSpecifier *S, CXXBasePath &) {
3975	if (S->getAccessSpecifier() == AccessSpecifier::AS_public) {
3976	CatchHandlerType Check(S->getType(), CheckAgainstPointer);
3977	const auto &M = TypesToCheck;
3978	auto I = M.find(Check);
3979	if (I != M.end()) {
3980	FoundHandler = I->second;
3981	FoundHandlerType = Ctx.getCanonicalType(S->getType());
3982	return true;
3983	}
3984	}
3985	return false;
3986	}
3987	};
3988	}
3989
3990	/// ActOnCXXTryBlock - Takes a try compound-statement and a number of
3991	/// handlers and creates a try statement from them.
3992	StmtResult Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
3993	ArrayRef<Stmt *> Handlers) {
3994	// Don't report an error if 'try' is used in system headers.
3995	if (!getLangOpts().CXXExceptions &&
3996	!getSourceManager().isInSystemHeader(TryLoc) && !getLangOpts().CUDA) {
3997	// Delay error emission for the OpenMP device code.
3998	targetDiag(TryLoc, diag::err_exceptions_disabled) << "try";
3999	}
4000
4001	// Exceptions aren't allowed in CUDA device code.
4002	if (getLangOpts().CUDA)
4003	CUDADiagIfDeviceCode(TryLoc, diag::err_cuda_device_exceptions)
4004	<< "try" << CurrentCUDATarget();
4005
4006	if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
4007	Diag(TryLoc, diag::err_omp_simd_region_cannot_use_stmt) << "try";
4008
4009	sema::FunctionScopeInfo *FSI = getCurFunction();
4010
4011	// C++ try is incompatible with SEH __try.
4012	if (!getLangOpts().Borland && FSI->FirstSEHTryLoc.isValid()) {
4013	Diag(TryLoc, diag::err_mixing_cxx_try_seh_try);
4014	Diag(FSI->FirstSEHTryLoc, diag::note_conflicting_try_here) << "'__try'";
4015	}
4016
4017	const unsigned NumHandlers = Handlers.size();
4018	(0) . __assert_fail ("!Handlers.empty() && \"The parser shouldn't call this if there are no handlers.\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 4019, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!Handlers.empty() &&
4019	(0) . __assert_fail ("!Handlers.empty() && \"The parser shouldn't call this if there are no handlers.\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 4019, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "The parser shouldn't call this if there are no handlers.");
4020
4021	llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> HandledTypes;
4022	for (unsigned i = 0; i < NumHandlers; ++i) {
4023	CXXCatchStmt *H = cast<CXXCatchStmt>(Handlers[i]);
4024
4025	// Diagnose when the handler is a catch-all handler, but it isn't the last
4026	// handler for the try block. [except.handle]p5. Also, skip exception
4027	// declarations that are invalid, since we can't usefully report on them.
4028	if (!H->getExceptionDecl()) {
4029	if (i < NumHandlers - 1)
4030	return StmtError(Diag(H->getBeginLoc(), diag::err_early_catch_all));
4031	continue;
4032	} else if (H->getExceptionDecl()->isInvalidDecl())
4033	continue;
4034
4035	// Walk the type hierarchy to diagnose when this type has already been
4036	// handled (duplication), or cannot be handled (derivation inversion). We
4037	// ignore top-level cv-qualifiers, per [except.handle]p3
4038	CatchHandlerType HandlerCHT =
4039	(QualType)Context.getCanonicalType(H->getCaughtType());
4040
4041	// We can ignore whether the type is a reference or a pointer; we need the
4042	// underlying declaration type in order to get at the underlying record
4043	// decl, if there is one.
4044	QualType Underlying = HandlerCHT.underlying();
4045	if (auto *RD = Underlying->getAsCXXRecordDecl()) {
4046	if (!RD->hasDefinition())
4047	continue;
4048	// Check that none of the public, unambiguous base classes are in the
4049	// map ([except.handle]p1). Give the base classes the same pointer
4050	// qualification as the original type we are basing off of. This allows
4051	// comparison against the handler type using the same top-level pointer
4052	// as the original type.
4053	CXXBasePaths Paths;
4054	Paths.setOrigin(RD);
4055	CatchTypePublicBases CTPB(Context, HandledTypes, HandlerCHT.isPointer());
4056	if (RD->lookupInBases(CTPB, Paths)) {
4057	const CXXCatchStmt *Problem = CTPB.getFoundHandler();
4058	if (!Paths.isAmbiguous(CTPB.getFoundHandlerType())) {
4059	Diag(H->getExceptionDecl()->getTypeSpecStartLoc(),
4060	diag::warn_exception_caught_by_earlier_handler)
4061	<< H->getCaughtType();
4062	Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(),
4063	diag::note_previous_exception_handler)
4064	<< Problem->getCaughtType();
4065	}
4066	}
4067	}
4068
4069	// Add the type the list of ones we have handled; diagnose if we've already
4070	// handled it.
4071	auto R = HandledTypes.insert(std::make_pair(H->getCaughtType(), H));
4072	if (!R.second) {
4073	const CXXCatchStmt *Problem = R.first->second;
4074	Diag(H->getExceptionDecl()->getTypeSpecStartLoc(),
4075	diag::warn_exception_caught_by_earlier_handler)
4076	<< H->getCaughtType();
4077	Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(),
4078	diag::note_previous_exception_handler)
4079	<< Problem->getCaughtType();
4080	}
4081	}
4082
4083	FSI->setHasCXXTry(TryLoc);
4084
4085	return CXXTryStmt::Create(Context, TryLoc, TryBlock, Handlers);
4086	}
4087
4088	StmtResult Sema::ActOnSEHTryBlock(bool IsCXXTry, SourceLocation TryLoc,
4089	Stmt TryBlock, Stmt Handler) {
4090	assert(TryBlock && Handler);
4091
4092	sema::FunctionScopeInfo *FSI = getCurFunction();
4093
4094	// SEH __try is incompatible with C++ try. Borland appears to support this,
4095	// however.
4096	if (!getLangOpts().Borland) {
4097	if (FSI->FirstCXXTryLoc.isValid()) {
4098	Diag(TryLoc, diag::err_mixing_cxx_try_seh_try);
4099	Diag(FSI->FirstCXXTryLoc, diag::note_conflicting_try_here) << "'try'";
4100	}
4101	}
4102
4103	FSI->setHasSEHTry(TryLoc);
4104
4105	// Reject __try in Obj-C methods, blocks, and captured decls, since we don't
4106	// track if they use SEH.
4107	DeclContext *DC = CurContext;
4108	while (DC && !DC->isFunctionOrMethod())
4109	DC = DC->getParent();
4110	FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(DC);
4111	if (FD)
4112	FD->setUsesSEHTry(true);
4113	else
4114	Diag(TryLoc, diag::err_seh_try_outside_functions);
4115
4116	// Reject __try on unsupported targets.
4117	if (!Context.getTargetInfo().isSEHTrySupported())
4118	Diag(TryLoc, diag::err_seh_try_unsupported);
4119
4120	return SEHTryStmt::Create(Context, IsCXXTry, TryLoc, TryBlock, Handler);
4121	}
4122
4123	StmtResult
4124	Sema::ActOnSEHExceptBlock(SourceLocation Loc,
4125	Expr *FilterExpr,
4126	Stmt *Block) {
4127	assert(FilterExpr && Block);
4128
4129	if(!FilterExpr->getType()->isIntegerType()) {
4130	return StmtError(Diag(FilterExpr->getExprLoc(),
4131	diag::err_filter_expression_integral)
4132	<< FilterExpr->getType());
4133	}
4134
4135	return SEHExceptStmt::Create(Context,Loc,FilterExpr,Block);
4136	}
4137
4138	void Sema::ActOnStartSEHFinallyBlock() {
4139	CurrentSEHFinally.push_back(CurScope);
4140	}
4141
4142	void Sema::ActOnAbortSEHFinallyBlock() {
4143	CurrentSEHFinally.pop_back();
4144	}
4145
4146	StmtResult Sema::ActOnFinishSEHFinallyBlock(SourceLocation Loc, Stmt *Block) {
4147	assert(Block);
4148	CurrentSEHFinally.pop_back();
4149	return SEHFinallyStmt::Create(Context, Loc, Block);
4150	}
4151
4152	StmtResult
4153	Sema::ActOnSEHLeaveStmt(SourceLocation Loc, Scope *CurScope) {
4154	Scope *SEHTryParent = CurScope;
4155	while (SEHTryParent && !SEHTryParent->isSEHTryScope())
4156	SEHTryParent = SEHTryParent->getParent();
4157	if (!SEHTryParent)
4158	return StmtError(Diag(Loc, diag::err_ms___leave_not_in___try));
4159	CheckJumpOutOfSEHFinally(this, Loc, SEHTryParent);
4160
4161	return new (Context) SEHLeaveStmt(Loc);
4162	}
4163
4164	StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc,
4165	bool IsIfExists,
4166	NestedNameSpecifierLoc QualifierLoc,
4167	DeclarationNameInfo NameInfo,
4168	Stmt *Nested)
4169	{
4170	return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists,
4171	QualifierLoc, NameInfo,
4172	cast<CompoundStmt>(Nested));
4173	}
4174
4175
4176	StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc,
4177	bool IsIfExists,
4178	CXXScopeSpec &SS,
4179	UnqualifiedId &Name,
4180	Stmt *Nested) {
4181	return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists,
4182	SS.getWithLocInContext(Context),
4183	GetNameFromUnqualifiedId(Name),
4184	Nested);
4185	}
4186
4187	RecordDecl*
4188	Sema::CreateCapturedStmtRecordDecl(CapturedDecl *&CD, SourceLocation Loc,
4189	unsigned NumParams) {
4190	DeclContext *DC = CurContext;
4191	while (!(DC->isFunctionOrMethod() \|\| DC->isRecord() \|\| DC->isFileContext()))
4192	DC = DC->getParent();
4193
4194	RecordDecl *RD = nullptr;
4195	if (getLangOpts().CPlusPlus)
4196	RD = CXXRecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc,
4197	/Id=/nullptr);
4198	else
4199	RD = RecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc, /Id=/nullptr);
4200
4201	RD->setCapturedRecord();
4202	DC->addDecl(RD);
4203	RD->setImplicit();
4204	RD->startDefinition();
4205
4206	(0) . __assert_fail ("NumParams > 0 && \"CapturedStmt requires context parameter\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 4206, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(NumParams > 0 && "CapturedStmt requires context parameter");
4207	CD = CapturedDecl::Create(Context, CurContext, NumParams);
4208	DC->addDecl(CD);
4209	return RD;
4210	}
4211
4212	static void
4213	buildCapturedStmtCaptureList(SmallVectorImpl<CapturedStmt::Capture> &Captures,
4214	SmallVectorImpl<Expr *> &CaptureInits,
4215	ArrayRef<sema::Capture> Candidates) {
4216	for (const sema::Capture &Cap : Candidates) {
4217	if (Cap.isThisCapture()) {
4218	Captures.push_back(CapturedStmt::Capture(Cap.getLocation(),
4219	CapturedStmt::VCK_This));
4220	CaptureInits.push_back(Cap.getInitExpr());
4221	continue;
4222	} else if (Cap.isVLATypeCapture()) {
4223	Captures.push_back(
4224	CapturedStmt::Capture(Cap.getLocation(), CapturedStmt::VCK_VLAType));
4225	CaptureInits.push_back(nullptr);
4226	continue;
4227	}
4228
4229	Captures.push_back(CapturedStmt::Capture(Cap.getLocation(),
4230	Cap.isReferenceCapture()
4231	? CapturedStmt::VCK_ByRef
4232	: CapturedStmt::VCK_ByCopy,
4233	Cap.getVariable()));
4234	CaptureInits.push_back(Cap.getInitExpr());
4235	}
4236	}
4237
4238	void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
4239	CapturedRegionKind Kind,
4240	unsigned NumParams) {
4241	CapturedDecl *CD = nullptr;
4242	RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, NumParams);
4243
4244	// Build the context parameter
4245	DeclContext *DC = CapturedDecl::castToDeclContext(CD);
4246	IdentifierInfo *ParamName = &Context.Idents.get("__context");
4247	QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD));
4248	auto *Param =
4249	ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4250	ImplicitParamDecl::CapturedContext);
4251	DC->addDecl(Param);
4252
4253	CD->setContextParam(0, Param);
4254
4255	// Enter the capturing scope for this captured region.
4256	PushCapturedRegionScope(CurScope, CD, RD, Kind);
4257
4258	if (CurScope)
4259	PushDeclContext(CurScope, CD);
4260	else
4261	CurContext = CD;
4262
4263	PushExpressionEvaluationContext(
4264	ExpressionEvaluationContext::PotentiallyEvaluated);
4265	}
4266
4267	void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
4268	CapturedRegionKind Kind,
4269	ArrayRef<CapturedParamNameType> Params) {
4270	CapturedDecl *CD = nullptr;
4271	RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, Params.size());
4272
4273	// Build the context parameter
4274	DeclContext *DC = CapturedDecl::castToDeclContext(CD);
4275	bool ContextIsFound = false;
4276	unsigned ParamNum = 0;
4277	for (ArrayRef<CapturedParamNameType>::iterator I = Params.begin(),
4278	E = Params.end();
4279	I != E; ++I, ++ParamNum) {
4280	if (I->second.isNull()) {
4281	(0) . __assert_fail ("!ContextIsFound && \"null type has been found already for '__context' parameter\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 4282, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!ContextIsFound &&
4282	(0) . __assert_fail ("!ContextIsFound && \"null type has been found already for '__context' parameter\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 4282, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "null type has been found already for '__context' parameter");
4283	IdentifierInfo *ParamName = &Context.Idents.get("__context");
4284	QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD))
4285	.withConst()
4286	.withRestrict();
4287	auto *Param =
4288	ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4289	ImplicitParamDecl::CapturedContext);
4290	DC->addDecl(Param);
4291	CD->setContextParam(ParamNum, Param);
4292	ContextIsFound = true;
4293	} else {
4294	IdentifierInfo *ParamName = &Context.Idents.get(I->first);
4295	auto *Param =
4296	ImplicitParamDecl::Create(Context, DC, Loc, ParamName, I->second,
4297	ImplicitParamDecl::CapturedContext);
4298	DC->addDecl(Param);
4299	CD->setParam(ParamNum, Param);
4300	}
4301	}
4302	(0) . __assert_fail ("ContextIsFound && \"no null type for '__context' parameter\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/SemaStmt.cpp", 4302, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(ContextIsFound && "no null type for '__context' parameter");
4303	if (!ContextIsFound) {
4304	// Add __context implicitly if it is not specified.
4305	IdentifierInfo *ParamName = &Context.Idents.get("__context");
4306	QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD));
4307	auto *Param =
4308	ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4309	ImplicitParamDecl::CapturedContext);
4310	DC->addDecl(Param);
4311	CD->setContextParam(ParamNum, Param);
4312	}
4313	// Enter the capturing scope for this captured region.
4314	PushCapturedRegionScope(CurScope, CD, RD, Kind);
4315
4316	if (CurScope)
4317	PushDeclContext(CurScope, CD);
4318	else
4319	CurContext = CD;
4320
4321	PushExpressionEvaluationContext(
4322	ExpressionEvaluationContext::PotentiallyEvaluated);
4323	}
4324
4325	void Sema::ActOnCapturedRegionError() {
4326	DiscardCleanupsInEvaluationContext();
4327	PopExpressionEvaluationContext();
4328
4329	CapturedRegionScopeInfo *RSI = getCurCapturedRegion();
4330	RecordDecl *Record = RSI->TheRecordDecl;
4331	Record->setInvalidDecl();
4332
4333	SmallVector<Decl*, 4> Fields(Record->fields());
4334	ActOnFields(/Scope=/nullptr, Record->getLocation(), Record, Fields,
4335	SourceLocation(), SourceLocation(), ParsedAttributesView());
4336
4337	PopDeclContext();
4338	PopFunctionScopeInfo();
4339	}
4340
4341	StmtResult Sema::ActOnCapturedRegionEnd(Stmt *S) {
4342	CapturedRegionScopeInfo *RSI = getCurCapturedRegion();
4343
4344	SmallVector<CapturedStmt::Capture, 4> Captures;
4345	SmallVector<Expr *, 4> CaptureInits;
4346	buildCapturedStmtCaptureList(Captures, CaptureInits, RSI->Captures);
4347
4348	CapturedDecl *CD = RSI->TheCapturedDecl;
4349	RecordDecl *RD = RSI->TheRecordDecl;
4350
4351	CapturedStmt *Res = CapturedStmt::Create(
4352	getASTContext(), S, static_cast<CapturedRegionKind>(RSI->CapRegionKind),
4353	Captures, CaptureInits, CD, RD);
4354
4355	CD->setBody(Res->getCapturedStmt());
4356	RD->completeDefinition();
4357
4358	DiscardCleanupsInEvaluationContext();
4359	PopExpressionEvaluationContext();
4360
4361	PopDeclContext();
4362	PopFunctionScopeInfo();
4363
4364	return Res;
4365	}
4366